United Kingdom by-election records

UK by-election records is an annotated list of notable records from United Kingdom by-elections. A by-election occurs when a Member of Parliament resigns, dies, or is disqualified or expelled, and an election is held to fill the vacant seat. A constituency is the seat or division that member represented.

Prior to 1945, electoral competition in the United Kingdom exhibited features which make meaningful comparisons with modern results difficult.

Among the most significant were:

*Frequent interventions and withdrawals of parties in different seats.
*Frequent Coalitions between parties, splits within parties and floor-crossing by members.
*Uncontested elections and truces between parties, in particular during both World Wars.
*Generally more significant competition from independent candidates and minor parties.
*Multi-member seats and University seats.
*Higher frequency of by-elections.
*Generally higher turnouts, although several wartime elections exhibited the lowest recorded turnouts.
*Generally higher variation in size of constituency electorates.

Since 1945, the evolution of a stable three-party system has tended to negate each of the above features so that, broadly speaking, elections are more comparable.

In Northern Ireland, as ever, the pattern of party competition is completely different from that on the mainland and comparisons remain problematic.

Hence, unless otherwise stated records are based on results since the 1945 General Election, and earlier exceptional results are listed separately.

For comparison purposes the following definitions have been adopted.

*Gain - victory by a party which was not victorious at the immediate previous election.
*Loss - defeat of a party which was victorious at the immediate previous election.
*Hold - victory by a party which was victorious at the immediate previous election.
*Win - victory by a party. Ambiguous term that could mean either a gain or a hold.
*Incumbent - the party which held the seat at the immediate previous election, irrespective of any intervening change of candidate or candidate's change of party.
*Third party - In England, since 1922, the "third party" has been the Liberal Party and its successors, the Liberal Democrats. Additionally, in Scotland and Wales the Scottish National Party (SNP) and Plaid Cymru are also considered to be third parties. Prior to 1922, the third party was the Labour Party.
*Minor party - parties smaller than the third party
*Uncontested - an election where only one candidate is put forward. No votes are actually cast and the candidate is by definition the victor.

Numerical records

For more information about what is meant by the term "swing", see Swing (politics)

Largest swings

Largest increase in percentage share of vote

The Stockport by-election, 1920, was held to elect two MPs. The winners' shares of the total vote were 25.6% and 25.1%. However, as each voter could cast two votes, the situation is not readily comparable to other by-elections in this period.

Lowest share of the vote

Major parties

Major parties winning 2% or less share of votes cast in a by-election, since 1918:

Still smaller majorities have been recorded since 1918. The majority in the Penrith and Cockermouth by-election, 1921, was only 31 votes, and in the Westminster Abbey by-election 1924 was 43 votes.

Turnout

Turnout is recorded as the percentage of valid votes from the total recorded vote.

Highest turnout

The highest turnouts since 1918:
*Mid Ulster by-election, 1969: 91.5%
*Mid Ulster by-election, 1955: 89.7%
*Ashton-under-Lyne by-election, 1928: 89.1%
*Fermanagh and South Tyrone by-election, August 1981: 88.6%
*Mid Ulster by-election, 1956: 88.4%
*Tiverton by-election, 1923: 88.1%
*Darlington by-election, 1926: 87.6%
*Carmarthen by-election, 1957: 87.4%
*Fermanagh and South Tyrone by-election, April 1981: 86.9%
*Stockport by-election, 1925: 85.7%
*Brighouse and Spenborough by-election, 1950: 85.4%

Turnout increased from general election

It is highly unusual for a by-election to attract a higher turnout in a seat than the previous general election.

:*¹ The most recent mainland UK example:*² Four of the eight straight fights were between the Unionist incumbent and a "paper candidate" using the name "Peter Barry", the name of the then Irish Foreign Minister.

Candidate records

Durable by-election candidates

Former Labour cabinet minister Tony Benn contested no fewer than four by-elections during his career, topping the poll on each occasion: Bristol South East in 1950, Bristol South East in 1961, Bristol South East in 1963 and Chesterfield in 1984. His first and last by-election victories were 33 years and 3 months apart.

Former cabinet minister and European Commissioner Roy Jenkins fought two different by-elections for the Social Democratic Party only eight months apart. He narrowly failed in the Warrington by-election, 1981 before winning the Glasgow Hillhead by-election, 1982. He had been first elected as a Labour MP almost 34 years previously in the Southwark Central by-election, 1948.

Former Speaker of the House of Commons, Betty Boothroyd finally secured election at her third by-election attempt at the West Bromwich by-election, 1973. She had previously failed in the Leicester South East by-election, 1957 and the Nelson and Colne by-election, 1968 as well as the General Elections of 1959 and 1970.

Fringe candidates Bill Boaks, Screaming Lord Sutch of the Official Monster Raving Loony Party and Tom Keen of the Campaign for a More Prosperous Britain contested numerous by-elections without success.

Pre-1945

Arthur Henderson was distinguished in being successful in no fewer than five by-elections in different seats, in Barnard Castle, Widnes, Newcastle-upon-Tyne East, Burnley, and Clay Cross.

Joseph Gibbins is the only person in modern times to gain the same seat twice in two different by-elections. He triumphed for Labour in the Liverpool West Toxteth by-election, 1924 and the Liverpool West Toxteth by-election, 1935.

William O'Brien won four by-elections, in Mallow in 1883, North East Cork in 1887 and then Cork City in 1904 and 1914. On these last two occasions, he was re-elected having resigned the seat.

Prime Minister Winston Churchill contested five by-elections in his long career:-
*Oldham by-election, 1899 in which he was not elected
*Manchester North-West by-election, 1908 where he was defeated
*Dundee by-election, 1908 where he was elected
*Dundee by-election, 1917 where he was re-elected. [Roy Jenkins "Churchill" (Macmillan, 2001), page 325 ISBN 0-333-78290-9]
*Westminster, Abbey by-election, 1924 in which he was unsuccessful

John Wilkes won the Aylesbury by-election, 1757, and was then elected in the Middlesex by-elections of February, March and April 1769, on each occasion being subsequently expelled from the House of Commons.

Former MPs making a comeback at a by-election

*South Antrim by-election, 2000¹: William McCrea returns after losing his Mid Ulster seat in the 1997 General Election.
*Kensington and Chelsea by-election, 1999: Michael Portillo returns after losing his Enfield Southgate seat at the 1997 General Election.
*Beckenham by-election, 1997: Jacqui Lait returns after losing her Hastings and Rye seat at the 1997 General Election.
*Epping Forest by-election, 1988: Steve Norris returns after losing his Oxford East seat at the 1987 General Election.
*Glasgow Govan by-election, 1988¹: Jim Sillars returns as an SNP MP. He had first sat as a Labour MP (later as Scottish Labour) for South Ayrshire between 1970 and 1979.
*Chesterfield by-election, 1984: Tony Benn returns after losing his redrawn Bristol East seat at the 1983 General Election.
*Beaconsfield by-election, 1982: Tim Smith returns after losing his Ashfield seat in the 1979 General Election.
*Glasgow Hillhead by-election, 1982²: Roy Jenkins returns after a spell as European Commissioner, then co-founding the Social Democratic Party (SDP). He had first sat as a Labour MP for Southwark Central fom 1948-50 and Birmingham Stechford from 1950-77.
*Crosby by-election, 1981¹: Shirley Williams returns as the first-elected SDP MP. She had first sat as a Labour MP for Hitchin 1964-74 and for Hertford and Stevenage 1974-79.
*Warrington by-election, 1981: Douglas Hoyle returns after losing his Nelson and Colne seat in the 1979 General Election.
*Southend East by-election, 1980: Teddy Taylor returns after losing his Glasgow Cathcart seat at the 1979 General Election.
*South West Hertfordshire by-election, 1979: Richard Page returns after losing his Workington seat in the 1979 General Election.
*Knutsford by-election, 1979: Jock Bruce-Gardyne returns after losing his South Angus seat at the October 1974 General Election.
*Clitheroe by-election, 1979: David Waddington returns after losing his Nelson and Colne seat at the October 1974 General Election.
*Glasgow Garscadden by-election, 1978: Donald Dewar returns after losing his Aberdeen South seat in the 1970 General Election.
*Newham South by-election, 1974: Nigel Spearing returns after losing his Acton seat in the February 1974 General Election.
*Merthyr Tydfil by-election, 1972²: Edward Rowlands returns after losing his Cardiff North seat in the 1970 General Election.
*Greenwich by-election, 1971: Guy Barnett returns after losing his South Dorset seat in the 1964 General Election.
*Southampton Itchen by-election, 1971: Bob Mitchell returns after losing his Southampton Test seat in the 1970 General Election.
*St. Marylebone by-election, 1970: Kenneth Baker returns after losing his Acton seat in the 1970 General Election.
*Chichester by-election, 1969: Christopher Chataway returns after losing his Lewisham North seat in the 1966 General Election.
*Brighton Pavilion by-election, 1969: Julian Amery returns after losing his Preston North seat in the 1966 General Election.
*New Forest by-election, 1968: Patrick McNair-Wilson returns after losing his Lewisham West seat in the 1966 General Election.
*Warwick and Leamington by-election, 1968: Dudley Smith returns after losing his Brentford and Chiswick seat in the 1966 General Election.
*West Derbyshire by-election, 1967: James Scott-Hopkins returns after losing his Cornwall North seat in the 1966 General Election.
*Brierley Hill by-election, 1967: Fergus Montgomery returns after losing his Newcastle East seat in the 1964 General Election.
*Honiton by-election, 1967: Peter Emery returns after losing his Reading seat in the 1966 General Election.
*Saffron Walden by-election, 1965: Peter Kirk returns after losing his Gravesend seat in the 1964 General Election.
*Salisbury by-election, 1965: Michael Hamilton returns after losing his Wellingborough seat in the 1964 General Election.
*East Grinstead by-election, 1965: Geoffrey Johnson-Smith returns after losing his Holborn and St. Pancras South seat in the 1964 General Election.
*Altrincham and Sale by-election, 1965: Anthony Barber returns after losing his Doncaster seat in the 1964 General Election.
*St. Marylebone by-election, 1963: Quintin Hogg returns after disclaiming his peerage. He had previously sat for Oxford 1938-1950.
*Kinross and West Perthshire by-election, 1963: Sir Alec Douglas-Home returns after disclaiming his peerage. He had previously sat for Lanark 1931-45 and 1950-51.
*Bristol South East by-election, 1963: Tony Benn returns after disclaiming his peerage. He had been debarred from sitting for the seat since 1961.
*Middlesbrough East by-election, 1962: Arthur Bottomley returns after losing his Rochester and Chatham seat in the 1959 General Election.
*Ebbw Vale by-election, 1960: Michael Foot returns after losing his Plymouth Devonport seat in the 1955 General Election.
*Bootle by-election, 1911: Andrew Bonar Law returns after failing to win Manchester North-West in the December 1910 General Election.
*Dundee by-election, 1908: Winston Churchill returns after losing his Manchester North West seat in a 1908 by-election, upon his appointment to the Board of Trade.
*Dulwich by-election, 1906: Andrew Bonar Law returns after losing his Glasgow Blackfriars and Hutchesontown seat in the 1906 General Election.
*City of London by-election, 1906: Arthur Balfour returns after losing his Manchester East seat in the 1906 General Election.Notes:

¹ by-election gain lost at the subsequent General Election

² by-election gain held at the subsequent General Election

Former MPs failing in a by-election

*Haltemprice and Howden by-election, 2008 - Former Vale of Glamorgan MP Walter Sweeney stands as an independent, winning 1% of the votes.
*Cheadle by-election, 2005: Stephen Day fails to regain for the Conservatives a seat he lost by only 33 votes four years previously.
*Winchester by-election, 1997: Gerald Malone fails disastrously to regain the seat for the Conservatives, after losing by only 2 votes six months previously.
*Christchurch by-election, 1993: Robert Hayward loses one of the Conservatives' safest seats to the Liberal Democrats.
*Eastbourne by-election, 1990: Richard Hickmet fails disastrously to defend the seat for the Conservatives, after publicly stating that for electors not to support him would be a moral victory for the Provisional Irish Republican Army.
*Pontypridd by-election, 1989: Tom Ellis, former Labour and SDP MP, stands for the Social and Liberal Democrats, losing his deposit.
*Fermanagh and South Tyrone by-election, 1986: Owen Carron fails to regain the seat for Sinn Féin that he held 1981-83.
*Peckham by-election, 1982: Dick Taverne, former Labour and Democratic Labour MP, stands for the SDP.
*Gower by-election, 1982: Gwynoro Jones, former Labour MP, stands for the SDP.
*Beaconsfield by-election, 1982: Paul Tyler fails for the Liberals in a by-election held during the Falklands War.
*Warrington by-election, 1981: Roy Jenkins narrowly fails to win for the SDP in its first parliamentary contest.
*Fermanagh and South Tyrone by-election, April 1981: Harry West fails to regain his old seat against Bobby Sands
*Hamilton by-election, 1978: Margo Macdonald fails to repeat the SNP's 1967 triumph.
*Ilford North by-election, 1978: Thomas Iremonger, who had sat for the seat 1954-74, stands as an independent Conservative, winning a mere 1.5% of the vote.
*Birmingham Stechford by-election, 1977: Terry Davis loses a safe Labour seat.
*Walsall North by-election, 1976: David Winnick loses a safe Labour seat.
*Liverpool Scotland by-election, 1971: Peter Mahon stands as an Independent Labour Anti-Abortion candidate, securing 10.3% of the vote.
*Brighton Pavilion by-election, 1969: Thomas Skeffington-Lodge stands for Labour in a safe Conservative seat, 19 years after losing his seat.
*Nuneaton by-election, 1967: Air Vice-Marshall Donald Bennett stands as a National Party candidate, 22 years after losing his seat as a Liberal MP.
*Salisbury by-election, 1965: Horace Trevor-Cox stands as an independent Conservative, 20 years after losing his seat.
*Leyton by-election, 1965: Patrick Gordon-Walker narrowly loses a supposed safe seat.
*South Dorset by-election, 1962: Angus Maude narrowly loses.
*Bolton East by-election, 1960: Frank Byers stands for the Liberals.
*Hereford by-election, 1956: Frank Owen fails to regain for the Liberals the seat he previously sat for 1929-1931
*Mid Ulster by-election, 1956: Michael O'Neill fails to regain the seat, a year after retiring as its MP.
*Westminster Abbey by-election, 1924: Winston Churchill narrowly fails to take the seat, as a Constitutionalist.
*Woolwich East by-election, 1921: Ramsay MacDonald loses a supposed safe Labour seat.
*Ipswich by-election, 1914: Charles Masterman loses again, effectively ending his political career.
*Bethnal Green South West by-election, 1914: Charles Masterman loses by-election prompted by his appointment as Chancellor of the Duchy of Lancaster.
*Manchester North West by-election, 1908: Winston Churchill loses by-election prompted by his appointment to the Board of Trade.

hortest-serving by-election victors

ince 1945

*Bobby Sands, Anti-H Block Fermanagh and South Tyrone by-election, April 1981 25 days ¹
*Michael Carr, Labour Bootle by-election, May 1990 57 days ¹
*Oswald O'Brien, Labour Darlington by-election, 1983 77 days ²
*Margo Macdonald, SNP Glasgow Govan by-election, 1973 112 days ²
*Charles Beattie, Unionist Mid Ulster by-election, 1955 123 days ³
*Nicol Stephen, Lib Dem Kincardine and Deeside by-election, 1991 154 days ²
*Ashok Kumar, Labour Langbaurgh by-election, 1991 154 days ^2a
*Helen McElhone, Labour Glasgow Queen's Park by-election, 1982 189 days ⁴
*David Austick, Liberal Ripon by-election, 1973 217 days ²
*John Spellar, Labour Birmingham Northfield by-election, 1982 224 days ^2a
*Christopher Ward, Conservative Swindon by-election, 1969 231 days ²
*William McCrea, DUP South Antrim by-election, 2000 259 days ^2ab
*Parmjit Singh Gill, Lib Dem Leicester South by-election, 2004 294 days ²
*David Colville Anderson, Conservative Dumfriesshire by-election, 1963 309 days ⁵
*Huw Edwards, Labour Monmouth by-election, 1991 329 days ^2a
*Thomas Teevan, Unionist Belfast West by-election, 1950 330 days ²
*Wallace Lawler, Liberal Birmingham Ladywood by-election, 1969 357 days ²
*George Machin, Labour Dundee East by-election, 1973 364 days ²

Notes
*¹ died
*² defeated at next general election
*³ disqualified (Beattie was never elected. He was awarded the seat on the disqualification of his predecessor, only to be found to be disqualified himself)
*⁴ retired at next general election (seat abolished by redistribution and failed to secure alternative seat)
*⁵ retired at next general election due to personal difficulties
*^a returned to Parliament at a subsequent election
*^b had served previously as an MP

Pre-1945

*Henry Francis Compton, Conservative New Forest by-election, 1905 46 days ²
*Ronald Bell, Conservative Newport by-election, 1945 70 days ^2a
*Donald Bennett, Liberal Middlesbrough West by-election, 1945 73 days ²
*John Dumphreys, Conservative Bermondsey by-election, 1909 83 days ²
*Seaborne Davies, Liberal Caernarvon Boroughs by-election, 1945 91 days ²
*Joseph Ormond Andrews, Liberal Barkston Ash by-election, 1905 97 days ²
*Dr Robert McIntyre, SNP Motherwell by-election, 1945 104 days ²
*Ruth Dalton, Labour Bishop Auckland by-election, 1929 112 days ³
*George Knox Anderson, Conservative Canterbury by-election, 1918 113 days ³
*Herbert Evans, Labour Gateshead by-election, 1931 121 days ¹
*Andrew Clarke, Labour Midlothian and Peebles North by-election, 1929 121 days ^2b
*Sir Henry Wilson, Unionist North Down by-election, February 1922 121 days ⁵
*Joseph Henderson, Labour Manchester Ardwick by-election, 1931 135 days ^2a
*Evan Cotton, Liberal Finsbury East by-election, 1918 151 days ²
*David Hardie, Labour Glasgow Rutherglen by-election, 1931 159 days ²
*Lord Arthur Hill, Unionist West Down by-election, 1907 193 days ^7b
*Oswald Cawley, Liberal Prestwich by-election, 1918 202 days ¹
*G. Banton, Labour Leicester East by-election, 1922 230 days ^2a
*William Henry Somervell, Liberal Keighley by-election, 1918 232 days ²
*Noel Edward Buxton, Liberal Whitby by-election, 1905 238 days ^2a
*Leslie Orme Wilson, Conservative Portsmouth South by-election, 1922 243 days ^7b
*Leah Manning, Labour Islington East by-election, 1931 250 days ^2a
*Frederick William Gibbins, Liberal Mid Glamorgan by-election, 1910 253 days ³
*C. V. F. Palmer, Independent The Wrekin by-election, 1920 261 days ¹
*Maurice Healy, Ind. Nationalist Cork City by-election, 1909 262 days ^2ab
*John Edward Sutton, Labour Manchester Clayton by-election, 1922 270 days ^2ab
*James Chuter Ede, Labour Mitcham by-election, 1923 278 days ^2a
*J. J. Cleary, Labour Liverpool Wavertree by-election, 1935 281 days ²
*Sir William Beveridge, Liberal Berwick-upon-Tweed by-election, 1944 282 days ²
*W. P. Sidney, Conservative Chelsea by-election, 1944 288 days ⁴
*Sir John Reith, National Southampton by-election, February 1940 293 days ⁶
*W. E. Gibbons, Conservative Bilston by-election, 1944 309 days ²
*Lord Charles Beresford, Conservative Woolwich by-election, 1902 320 days ^7ab
*Arthur Henderson, Labour Newcastle East by-election, 1923 323 days ^2ab
*James Henry Hall, Labour Whitechapel and St.George's by-election, 1931 328 days ^2a
*Thomas Naylor, Labour Southwark South East by-election, 1921 336 days ^2a

*¹ died
*² defeated at next general election
*³ retired at next general election
*⁴ retired at next general election, upon succession to a peerage
*⁵ assassinated by IRA
*⁶ elevated to the Peerage
*⁷ resigned
*^a returned to Parliament at a subsequent election
*^b had served previously as an MP

Youngest by-election victors

* Esmond Harmsworth, elected on 15 November 1919 from Isle of Thanet aged 21 years 170 days. [Since the Reform Act 1832; of those whose age can be verified.]
* Youngest woman: Bernadette Devlin, elected on 17 April 1969 from Mid Ulster aged 21 years 359 days.

Babies of the House elected at by-elections

"See" Baby of the House of Commons

Oldest by-election victors

*James Patrick Mahon was 79 when he held the Clare by-election, 1879 and 87 when he held the County Carlow by-election, 1887 for the Irish Nationalists.
*Henry Bruce Armstrong was 76 when he held the Mid Armagh by-election, 1921 for the Ulster Unionists.
*Enoch Powell was 73 when he successfully defended his seat at the South Down by-election, 1986, although he had been an MP almost continuously since 1950.
*Sir George Reid was 70 when he held the St. George's, Hanover Square by-election, 1916 for the Conservatives. He was a former Prime Minister of Australia.
*Arthur Salter was 70 when he held the Ormskirk by-election, 1951 for the Conservatives. He had served previously as MP for Oxford University 1937-50.
*John Evans was 70 when he held the Ogmore by-election, 1946 for Labour.
*David Hardie, the half-brother of Keir Hardie, was thought to be about 70 when he held the Glasgow Rutherglen by-election, 1931 for Labour.
*George Edwards was almost 70 when he gained the South Norfolk by-election, 1920 for Labour. He was an agricultural labourer.

First women by-election victors

The first woman to be elected in a by-election was Nancy Astor, who succeeded her husband at the Plymouth Sutton by-election, 1919, becoming the first woman to take her seat in the House of Commons.

The first woman to gain a seat in a by-election was Susan Lawrence who won the East Ham North by-election, 1926, although she had previously sat for the same seat between 1923-4.¹

The first woman to gain a seat "ab initio" in a by-election was Jennie Lee who won the North Lanarkshire by-election, 1929, at the same time becoming the first woman Baby of the House of Commons.

Note¹Mabel Philipson succeeded her husband at the Berwick-upon-Tweed by-election, 1923. He had been elected as a National Liberal. She won as a Conservative so this could arguably be classed as the first gain by a woman.

First ethnic minority by-election victors

Whilst the first ethnic minority Members of Parliament were elected as early as the 1890s, it would be almost 100 years before one was returned at a by-election.

The first ethnic minority candidate to be elected in a by-election was Ashok Kumar who gained the Langbaurgh by-election, 1991 for Labour.

*David Lammy held the Tottenham by-election, 2000 for Labour.
*Mark Hendrick held the Preston by-election, 2000 for Labour.
*Parmjit Singh Gill gained the Leicester South by-election, 2004 for the Liberal Democrats.

The first by-election in which all three major-party candidates were from the ethnic minorities was the Ealing Southall by-election, 2007, held by Labour.

First by-election victors from specific religions

When the UK Parliament was established in 1801, non-Anglicans were prevented from taking their seats as MPs under the Test Act 1672. However, Methodists took communion at Anglican churches until 1795, and some continued to do so, and many Presbyterians were prepared to accept Anglican communion, thus ensuring that members of these creeds were represented in the Parliament. [Chris Pond, [http://www.parliament.uk/commons/lib/research/notes/snpc-01493.pdf Parliament and Religious Disabilities] ] Some Unitarians were also elected.

The first Roman Catholic by-election victor in the UK Parliament was Daniel O'Connell in the Clare by-election, 1828. He was not permitted to take his seat until the following year.

David Salomons was the first Jewish by-election victor, at the Greenwich by-election, 1851.

Parmjit Singh Gill became the first Sikh by-election victor, at the Leicester South by-election, 2004.

By-elections losers awarded seats on disqualification of winner

*Malcolm St Clair, Bristol South East by-election, 1961
*Charles Beattie, Mid Ulster by-election, 1955

Two or more former MPs contest by-election

* Haltemprice and Howden by-election, 2008¹
* Winchester by-election, 1997
* Fermanagh and South Tyrone by-election, 1986
* Beaconsfield by-election, 1982
* Warrington by-election, 1981
* Brighton Pavilion by-election, 1969
* Salisbury by-election, 1965
* Mid Ulster by-election, 1956
* Croydon North by-election, 1948
* Altrincham by-election, 1933 (three former MPs)
* Glasgow Shettleston by-election, 1930
* Nottingham Central by-election, 1930 (three former MPs)
* Cheltenham by-election, 1928

¹ Conservative MPs David Davis and Walter Sweeney

Frequency and duration records

Longest period without a by-election

All periods of over a year between by-elections are listed:
*20 November 1997 - 10 June 1999: 567 days
*7 November 1991 - 6 May 1993: 546 days
*12 March 1987 - 14 July 1988: 489 days
*14 February 2002 - 18 June 2003: 489 days
*23 May 1974 - 26 June 1975: 399 days
*18 June 2003 - 15 July 2004: 393 days
*29 June 2006 - 19 July 2007: 385 days

Notes. 1992 and 1998 are the only calendar years in history without a single by-election. Since 1992 was nonetheless a General Election year, 1998 stands as the only year in British history without any parliamentary election.

Longest period without a seat changing hands

The longest period without a seat changing hands in a by-election was the five years between the Conservative victories in the Glasgow Camlachie by-election, 1948 and the Sunderland South by-election, 1953.

During the short Parliaments of 1910, 1950-1 and 1974 no seats changed hands in a by-election.

Longest period between by-election gains for a party

The Liberal Party endured 29 years without a single by-election gain between the Holland and Boston by-election, 1929 and the Torrington by-election, 1958. It did not win a single by-election in the thirteen years between holding the Middlesbrough West by-election, 1945 and gaining Torrington.

Until the Crewe and Nantwich by-election, 2008, the opposition Conservative Party had not gained a seat in almost 26 years, the last being the Mitcham and Morden by-election, 1982, which occurred during the unique cirmcumstances of the Falklands War and the sitting Labour MP defecting to the Social Democratic Party and seeking re-election under his new party label. The Conservatives' last gain while in Opposition was 30 years previously at the Ilford North by-election, 1978.

Labour's longest lean stretch was almost 18 years, between gaining the Brecon and Radnor by-election, 1939 and the Lewisham North by-election, 1957.¹

Note¹ The Labour Party were the official opposition in the Parliament elected in 1935, but after the major parties agreed an electoral truce on the outbreak of war in 1939, they did not contest any Conservative or Liberal seats for the remainder of the Parliament, a period of six years, and were members of the wartime coalition government between May 1940 and May 1945.

Longest period between by-election holds for a party

The Conservatives did not successfully defend a single by-election in the eight years between their holds of the Richmond by-election, 1989 and the Uxbridge by-election, 1997, losing a record 15 consecutive seats where they were the incumbents.

Labour's worst run was in losing 4 by-elections on the trot, which has occurred three times since 1945:

between holding the Newcastle-upon-Tyne Central by-election, 1976 and the Grimsby by-election, 1977.

between holding the Manchester Gorton by-election, 1967 and the Sheffield Brightside by-election, 1968.

between holding the Rhondda West by-election, 1967 and the Manchester Gorton by-election, 1967.

Longest period without an opposition gain

For a period of 11 years, until the Crewe and Nantwich by-election, 2008, the principal opposition Conservative Party failed to register a by-election gain against the incumbent Labour Government. This is the longest period of such failure since records began, and more than twice the previous record of the five years it took the then Labour opposition to gain the Lewisham North by-election, 1957.

Apart from the brief parliaments of 1910, 1950-1 and 1974, the parliaments of 1951-5 and 1997-2001 are the only occasions when the Government did not lose a by-election.

Most by-elections in one day

The largest number of by-elections held on a single day occurred on 23 January 1986 when 15 simultaneous contests were held in Northern Ireland. The elections had been engineered by the incumbent Unionist parties as a protest against the Anglo-Irish Agreement of 1985. They intended the results to be interpreted as a referendum on the treaty. The elections were boycotted by the main Nationalist parties except in four seats where they had a reasonable prospect of victory. In the event, the Social Democratic and Labour Party gained one seat, Newry and Armagh, from the Ulster Unionist Party.

Apart from the above example, it is common for UK mainland parties to schedule several by-elections on the same day. Motivations include attempting to divide opponents' resources and getting bad news (expected losses) out of the way. Since 1945, the largest number of simultaneous mainland by-elections has been 6, held on 16 November 1960. On four occasions, 5 by-elections have been held on the same day, most recently on 9 June 1994. Groupings of two or three are very common.

Most by-election losses in one day

The largest number of by-elections lost on a single day is three, when the Labour party lost Acton, Dudley and Meriden on 28 March 1968, all to the Conservatives.

Occasions since 1945 when two seats have fallen are:
*7 November 1991
**Kincardine and Deeside by-election, 1991 Liberal Democrat gain from Conservative
**Langbaurgh by-election, 1991 Labour gain from Conservative
*4 November 1976
**Walsall North by-election, 1976 Conservative gain from Labour
**Workington by-election, 1976 Conservative gain from Labour
*8 November 1973
**Glasgow Govan by-election, 1973 SNP gain from Labour
**Berwick-upon-Tweed by-election, 1973 Liberal gain from Conservative
*26 July 1973
**Ripon by-election, 1973 Liberal gain from Conservative
**Isle of Ely by-election, 1973 Liberal gain from Conservative
*2 November 1967
**Hamilton by-election, 1967 SNP gain from Labour
**Leicester South-West by-election, 1967 Conservative gain from Labour
*21 September 1967
**Walthamstow West by-election, 1967 Conservative gain from Labour
**Cambridge by-election, 1967 Conservative gain from Labour
*22 November 1962
**Glasgow Woodside by-election, 1962 Labour gain from Conservative
**South Dorset by-election, 1962 Labour gain from Conservative

eats with more than one by-election in a single Parliament

*Bootle: May and November 1990.
*Fermanagh and South Tyrone: April and August 1981.
*Bristol South East: 1961 and 1963.
*Mid Ulster: 1955 and 1956.
*Edinburgh East: 1945 and 1947.
*Middlesbrough West: 1940 and 1945.
*Combined Scottish Universities: 1936, 1938 and 1945.
*Berwick-upon-Tweed: 1941 and 1944.
*Clay Cross: 1936 and 1944.
*West Derbyshire: 1938 and 1944.
*Buckingham: 1937 and 1943.
*Manchester Gorton: 1937 and 1942.
*Dunbartonshire: 1936 and 1941.
*Greenock: 1936 and 1941.
*Doncaster: 1938 and 1941.
*Southampton: February and November 1940.
*Preston: 1936 and 1940.
*Wandsworth Central: 1937 and 1940.
*City of London: 1938 and 1940.
*Combined Scottish Universities: 1934 and 1935.
*Eastbourne: 1932 and 1935.
*Twickenham: 1932 and 1934.
*Portsmouth South: 1922 and 1923.
*North Down: 1921, February and July 1922.
*West Down: 1921 and 1922.
*South Londonderry: 1921 and 1922.
*Louth: 1920 and 1921.
*The Wrekin: February and November 1920.
*Londonderry North: 1919 and 1922.

Other seats with by-elections less than five years apart

*Nuneaton: 1965 and 1967.
*Ormskirk: 1951 and 1953.
*Liverpool Wavertree: 1931 and 1935.

By-election days

Currently, all British Parliamentary elections are invariably held on a Thursday. The last by-election not held on a Thursday was the Hamilton by-election, 1978, held on Wednesday 31 May due to a World Cup opening match on the Thursday evening.

Due to an administrative oversight, the Manchester Exchange by-election, 1973 was held on Wednesday 27 June 1973. Prior to that, the last by-elections not held on a Thursday were the Saffron Walden by-election, 1965 held on Tuesday 23 March, and the Roxburgh, Selkirk and Peebles by-election, 1965 held the following day.

Until the mid-1960s, it was common to hold by-elections on any day of the week (other than Sunday).

Causes of by-elections

By-elections prompted by assassination

*Eastbourne by-election, 1990: Ian Gow was killed by a Provisional IRA bomb under his car, 30 July 1990
*Enfield Southgate by-election, 1984: Sir Anthony Berry was killed in the Provisional IRA Brighton hotel bombing, 12 October 1984.
*Belfast South by-election, 1982: Rev. Robert Bradford was shot at a constituency surgery by the Provisional IRA, 14 November 1981.
*North Down by-election, July 1922: Field Marshal Sir Henry Wilson, Bt. was shot by the IRA outside his home, 22 June 1922.

By-elections prompted by accidental death

*Romsey by-election, 2000: Michael Colvin was killed by a house fire.
*Eastleigh by-election, 1994: Stephen Milligan accidentally choked himself while attempting autoerotic asphyxia.
*Bradford South by-election, 1994: Bob Cryer was killed in a car accident.
*Truro by-election, 1987: David Penhaligon was killed in a car accident.
*Rotherham by-election, 1963: Jack Jones was killed in a car accident.
*South West Norfolk by-election, 1959: Sidney Dye was killed in a car accident.
*Islington North by-election, 1958: Wilfred Fienburgh was killed in a car accident.
*Ipswich by-election, 1957: Richard Stokes died from injuries received in a car accident.
*North Down by-election, 1953: Sir Walter Smiles was killed in the MV Princess Victoria disaster during the storm surge.
*Dundee East by-election, 1952: Thomas Cook was killed in a car accident.
*Edmonton by-election, 1948: Evan Durbin was drowned while swimming.
*Stirling and Falkirk by-election, 1948: Joseph Westwood was killed in a car accident.
*Armagh by-election, 1948: Sir William Allen was killed in a car accident.
*Liverpool Edge Hill by-election, 1947: Dr Richard Clitherow died due to an overdose of barbiturates after he had been "run down and jaded". A verdict of accidental death was recorded at the inquest. Clitherow was a Medical Doctor and had taken seven barbitone tablets, described by the pathologist as a "bold dose". See "The Times", 19 June 1947, p. 2.]
*Glasgow Cathcart by-election, 1946: Francis Beattie was killed in a car accident.
*Smethwick by-election, 1945: Alfred Dobbs was killed in a car accident.
*Motherwell by-election, 1945: James Walker was killed in a road accident.
*Bury St. Edmunds by-election, 1944: Lieut-Col. Frank Heilgers was killed in a train crash.
*Manchester Clayton by-election, 1942: John Jagger was killed in a motorcycle accident.
*Stretford by-election, 1939: Anthony Crossley was killed in an air crash.

By-elections prompted by suicide

*Paisley South by-election, 1997: Gordon McMaster committed suicide.
*Mid Staffordshire by-election, 1990: John Heddle committed suicide.
*Birmingham Northfield by-election, 1982: Jocelyn Cadbury committed suicide.
*Fermanagh and South Tyrone by-election, August 1981: Bobby Sands continued his hunger strike until death.
*Acton by-election, 1968: Bernard Floud committed suicide.
*Harrow West by-election, 1959: Sir Albert Braithwaite committed suicide.
*Leeds West by-election, 1949: Thomas Stamford committed suicide.
*Jarrow by-election, 1947: Ellen Wilkinson committed suicide.
*Heywood and Radcliffe by-election, 1946: John Whittaker committed suicide.
*City of Chester by-election, 1940: Sir Charles Cayzer committed suicide after killing his butler.
*Wells by-election, 1939: Anthony Muirhead committed suicide.

By-elections prompted by posthumous election of MP

*Bromley by-election, 1945: Sir Edward Taswell Campbell died before his election declaration at the 1945 General Election.
*Monmouth by-election, 1945: Leslie Pym died before his election declaration at the 1945 General Election.
*Combined Scottish Universities by-election, 1935: Noel Skelton died before his election declaration at the 1935 General Election.
*North Galway by-election, 1906: Thomas Higgins died before his election declaration at the 1906 General Election.

By-elections prompted by scandal

*Beckenham by-election, 1997: Piers Merchant resigned after a newspaper story revealed that his previous denials of an affair were lies.
*Bournemouth East by-election, 1977: John Cordle resigned after he was criticised by a Select Committee for business links to corrupt architect John Poulson.
*Walsall North by-election, 1976: John Stonehouse resigned after being convicted of insurance fraud.
*Berwick-upon-Tweed by-election, 1973: Antony Lambton resigned after his visits to prostitutes and use of cannabis were exposed by the "News of the World".
*Stratford-upon-Avon by-election, 1963: John Profumo resigned after his denials of an affair with Christine Keeler were shown to be lies.
*Harrow East by-election, 1959: Ian Harvey resigned after conviction for gross indecency with a guardsman in Hyde Park.
*Paddington North by-election, 1953: Bill Field resigned after conviction for importuning for immoral purposes in a public lavatory.
*Sowerby by-election, 1949: John Belcher resigned after being found to have accepted gifts from businessmen for political favours.
*Scarborough and Whitby by-election, 1941: Sir Paul Latham resigned after he was arrested to be tried by court-martial on 13 charges of disgraceful conduct.
*Derby by-election, 1936: James Henry Thomas resigned after being found to have disclosed budget secrets.
*Buckrose by-election, 1926: Guy Gaunt resigned after being cited as co-respondent in a divorce case.

By-elections prompted to provide seat for seat-less personality

*Nuneaton by-election, 1965: For Frank Cousins.
*Leyton by-election, 1965: For Patrick Gordon-Walker (defeated).
*Sheffield Neepsend by-election, 1950: For Frank Soskice.
*City of London by-election, 1906: For Arthur Balfour.

By-elections prompted by party splits or disputes

*Bermondsey by-election, 1983: Robert Mellish, disenchanted with the left-wing takeover of his Constituency Labour Party (CLP), obtained a job with the London Docklands Development Corporation, left the Labour Party and then resigned to force a byelection.
*Lincoln by-election, 1973: Dick Taverne sought re-election as an Independent 'Democratic Labour' candidate after being deselected by his CLP; he was successful.
*Southwark by-election, 1972: Ray Gunter resigned from the Labour Party in disagreement with its stance opposing European Economic Community entry, and then from Parliament because he had been elected as a Labour candidate.
*Liverpool Garston by-election, 1957: Victor Raikes resigned the Conservative whip over the withdrawal from Suez, and then resigned from Parliament on obtaining a business appointment in Southern Rhodesia.
*Wednesbury by-election, 1957: Stanley Evans, a supporter of the Conservative government's Suez policy, resigned after being asked to by his Constituency Labour Party.
*Melton by-election, 1956: Anthony Nutting resigned in protest at government policy on Suez.

By-elections re-contested over a single issue

*Haltemprice and Howden by-election, 2008: David Davis resigned to force a by-election on the issue of civil liberties. He was re-elected as neither of the other main parties contested the seat.
*Northern Ireland by-elections, 1986: Fifteen Unionist MPs resigned and re-contested their seats in protest at the Anglo-Irish Agreement, all but one successful in gaining re-election.
*Kinross-shire and Perthshire by-election, 1938: The Duchess of Atholl resigned in protest at Neville Chamberlain's appeasement policy and sought re-election. She was defeated.
*Southwark North by-election, 1927: Leslie Haden-Guest resigned from the Labour Party over its policy on China, and re-contested the seat as an Independent Constitutionalist with Conservative support. He was unsuccessful, finishing bottom of the poll. The Liberals gained the seat.
*Cork City by-election, 1914: William O'Brien resigned to submit himself to the voters after the Irish Nationalists had made council gains in Cork. He was returned unopposed.
*Bow and Bromley by-election, 1912: George Lansbury resigned to contest his seat on the issue of Women's Suffrage, although he was disenchanted with a range of Labour party policies. He was defeated.
*Stratford-on-Avon by-election, 1909: Thomas Kincaid-Smith resigned from the Liberal Party on the issue of compulsory national service. He stood as an Independent with National Service League support. He was defeated, finishing bottom of the poll.
*Mid Cork by-election, 1906: D. D. Sheehan resigned and re-contested his seat following his expulsion from the Irish Nationalist group for not signing the party pledge. Re-elected as an independent.

By-elections to ratify a change of party

By-elections are ostensibly to vote for a 'person', not a 'party', meaning theoreticaly that a member switching parties mid-term is not cause for a by-election. However, some members do seek re-election under their new party as a point of principle.

*Merton, Mitcham and Morden by-election, 1982: Bruce Douglas-Mann honoured a pledge to seek re-election when he left Labour to join the SDP. He was defeated by the Conservative candidate.
*Lincoln by-election, 1973: Dick Taverne resigned and successfully re-contested his seat following his resignation from the Labour Party.
*Preston by-election, 1929: William Allen Jowitt resigned and successfully re-contested his seat having left the Liberal Party and joined Labour.
*Kingston-upon-Hull Central by-election, 1926: Joseph Kenworthy resigned and successfully re-contested his seat having left the Liberal Party and joined Labour.
*Isle of Wight by-election, 1904: J. E. B. Seely resigned and successfully recontested his seat having left the Conservative Party
*Orkney and Shetland by-election, 1902: Cathcart Wilson resigned and successfully recontested his seat having left the Liberal Party.

By-elections triggered when members leaves on principle

*Bristol South East by-election, 1963: Malcolm St Clair honoured a pledge to stand down if law changed to allow Tony Benn to disclaim his peerage.
*Edinburgh Leith by-election, 1927: William Wedgwood Benn resigned following his resignation from the Liberal party and joining the Labour Party. He did not contest the by-election out of fairness to the existing Labour candidate. The seat was narrowly held by a new Liberal candidate.

By-elections prompted by Member's desire to contest another seat

*East Tyrone by-election, 1918: William Redmond resigned in order to defend his late father's seat at Waterford City. He was successful.
*East Worcestershire by-election, 1914: Austin Chamberlain resigned in order to defend his late father's seat at Birmingham West. He was successful.
*East Wicklow by-election, 1911: John Muldoon resigned in order to contest the East Cork by-election. He was successful.

By-elections prompted by Election Courts

*Winchester by-election, 1997: The result of the 1997 general election was declared void because ballot papers which had not received the official mark would have affected the result, if counted. Liberal Democrat Mark Oaten massively increased the minute majority he had achieved in the general election.
*Mid Ulster by-election, 1955: The result of the 1955 general election was declared void because the successful candidate was disqualified as a felon.
*Oxford by-election, 1924: The result of the 1923 UK general election was declared void because there were irregularities in the election expenses of the successful candidate.
*Berwick-upon-Tweed by-election, 1923: The result of the 1922 UK general election was declared void because there were irregularities in the election expenses of the successful candidate.

By-elections prompted by disqualification of the sitting Member

*Bristol South East by-election, 1961: Tony Benn had inherited a Peerage from his father. Although by-elections were routinely called where Members had succeeded to the Peerage, the seat was not considered vacated until the Member had received a Writ of Summons to the House of Lords, and Benn, who refused to accept the Peerage, did not apply for one. The seat was declared vacant by a resolution of the House of Commons.
*Mid Ulster by-election, 1956: Charles Beattie was found to be disqualified through membership of National Assistance panels. A bill indemnifying him was passed by the House of Commons; Beattie did not stand in the by-election.
*Belfast West by-election, 1950: Rev James Godfrey MacManaway was found by the Judicial Committee of the Privy Council to be disqualified as a Minister of the Church of Ireland.
*Walsall by-election, 1925: Charles William Preston was found to be disqualified owing to his holding government contracts. A bill indemnifying him was passed by the House of Commons and Preston was re-elected at the by-election.
*Dover by-election, 1924: John Astor was disqualified for voting before he took the oath. He was returned unopposed at the by-election.
*Whitechapel by-election, 1913: Sir Stuart Samuel was found to be disqualified owing to his holding government contracts. A bill indemnifying him was passed by the House of Commons and Samuel was narrowly re-elected at the by-election.

By-elections prompted by expulsion from the House

*Norfolk South by-election, 1955: Peter Baker was expelled after being convicted of uttering, forgery and fraud.
*Gravesend by-election, 1947: Garry Allighan was expelled after being found to be in extreme contempt of the House by his peers.
*Hackney South by-election, 1922: Horatio Bottomley was expelled after being convicted of fraud, perjury and false accounting.

By-elections prompted by lunacy

*Colne Valley by-election, 1916: Charles Leach was adjudged a lunatic and his seat declared vacant.

By-elections prompted by bankruptcy

*Ashton-under-Lyne by-election, 1928: Cornelius Homan resigned before being declared bankrupt.
*North Galway by-election, 1914: Richard Hazelton resigned before being declared bankrupt. He discharged his bankruptcy and was returned in the by-election.
*South Kilkenny by-election, 1909: Nicholas Joseph Murphy was declared bankrupt.

By-elections prompted for miscellaneous reasons

*Widnes by-election, 1916: William Hall Walker resigned to permit him to donate his thoroughbred racing stock to create a National Stud in an "arms-length" transaction. He was returned unopposed at the by-election.

By-elections prompted by death of member on wartime active service

econd World War

*Chelmsford by-election, 1945: John Macnamara was killed in action fighting in Italy.
*Berwick-upon-Tweed by-election, 1944: George Charles Grey was killed in action fighting in Normandy, France.
*Bury St. Edmunds by-election, 1944: Frank Heilgers was killed in a train crash in Ilford.
*Acton by-election, 1943: Hubert Duggan died of tuberculosis contracted on active service. ^a
*Darwen by-election, 1943: Stuart Russell died of fever on active service in Egypt.
*Chippenham by-election, 1943: Victor Cazalet was killed in a plane crash in Gibraltar while escorting General Sikorski.
*Birmingham Aston by-election, 1943: Edward Orlando Kellett was killed in action fighting in North Africa.
*Buckingham by-election, 1943: John Whiteley was killed in a plane crash in Gibraltar while escorting General Sikorski.
*Bristol Central by-election, 1943: Lord Apsley was killed in action in a plane crash in the Middle-East.
*King's Lynn by-election, 1943: Somerset Maxwell died of wounds received at the Battle of El Alamein.
*Salisbury by-election, 1942: James Despencer-Robertson died suddenly, apparently from overwork as military secretary at Southern Command Headquarters. ^b
*Llandaff and Barry by-election, 1942: Patrick Munro died while taking part in an exercise for the Home Guard at Westminster.
*The Wrekin by-election, 1941: James Baldwin-Webb drowned when the SS City of Benares was torpedoed.
*Dudley by-election, 1941: Dudley Joel was killed in action while serving with the Royal Navy.
*Bodmin by-election, 1941: John Rathbone was killed in action on bombing operations over Germany.
*Hitchin by-election, 1941: Sir Arnold Wilson was killed in action over northern France while a gunner in Bomber Command
*King's Norton by-election, 1941: Ronald Cartland was killed in action during the retreat to Dunkirk.
*Manchester Exchange by-election, 1940: Peter Eckersley was killed in action in a plane crash while serving with the Fleet Air Arm.
*Heywood and Radcliffe by-election, 1940: Richard Porritt was killed in action fighting in Belgium.
*Wells by-election, 1939: Anthony Muirhead committed suicide owing to his fear that a leg-injury might prevent his service in the War. ^b

:Notes: The above list is of those members either mentioned as having died on War Service in a written Commons answer from Prime Minister Winston Churchill on 19 January 1945, or who appear in the "House of Commons Book of Remembrance" unveiled in 1949.

:^a Mentioned in the written Commons answer, but does not appear in the "House of Commons Book of Remembrance".:^b Not mentioned in the written Commons answer, but does appear in the "House of Commons Book of Remembrance".

:NB:- The above list does not include the names of three members who deaths on active service were overtaken by the 1945 General Election. For a complete list see Records of members of parliament of the United Kingdom#Second World War

First World War

*Prestwich by-election, 1918
*Bath by-election, 1918
*Ross by-election, 1918
*Manchester South by-election, 1918
*Wisbech by-election, 1917
*Spalding by-election, 1917
*East Clare by-election, 1917
*Henley by-election, 1917
*Winchester by-election, 1916
*Tewkesbury by-election, 1916
*St. Austell by-election, 1915
*Cardiff by-election, 1915
*Uxbridge by-election, 1915
*Heywood by-election, 1915
*Kilmarnock by-election, 1915
*Mid-Antrim by-election, 1915

Miscellaneous records

Incumbents fall directly from first place to third place

*Littleborough and Saddleworth by-election, 1995 Conservatives loss, gained by the Liberal Democrats
*Perth and Kinross by-election, 1995 Conservative loss, gained by the SNP
*Eastleigh by-election, 1994 Conservative loss, gained by the Liberal Democrats
*Brecon and Radnor by-election, 1985 Conservative loss, gained by the Liberals
*Mitcham and Morden by-election, 1982¹ Labour loss, gained by the Conservatives
*Rochdale by-election, 1958 Conservative loss, gained by Labour
*Merthyr by-election, 1934 ILP loss, gained by Labour
*Holland-with-Boston by-election, 1929 Conservative loss, gained by the Liberals
*Bosworth by-election, 1927 Conservative loss, gained by the Liberals
*Hull Central by-election, 1926² Liberal loss, gained by Labour
*South Norfolk by-election, 1920 Liberal loss, gained by Labour

:¹ Bruce Douglas-Mann had been re-elected as Labour MP for the seat in the 1979 General Election. In 1981, along with several other MPs, he defected to the newly-formed Social Democratic Party. Against his new colleagues' advice, he honoured a pledge to face his electors under his new party colours and precipitated a by-election. He came second in the by-election which was won by the Conservatives. The new Labour candidate finished third.

:² the Liberal MP, Lt-Commander the Hon. Joseph Montague Kenworthy, defected to Labour and sought re-election under his new colours. He was successful, and the new Liberal candidate lost his deposit.

Incumbent Governments gain seats

These records show the rare occasions when the Government won a seat they had not won at the previous General election.

Conservative

*Mitcham and Morden by-election, 1982, from Labour
*Bristol South-East by-election, 1961¹, from Labour
*Brighouse and Spenborough by-election, 1960, from Labour
*Sunderland South by-election, 1953, from Labour
*Combined English Universities by-election, 1926, from the Liberals
*Hackney South by-election, 1922, from the Independent Parliamentary Group
*Woolwich East by-election, 1921, from Labour
*Stockport by-election, 1920, from Coalition Labour²

:¹ Seat awarded by Election Court to Conservative runner-up because Labour victor deemed ineligible.:² An arguable gain; Stockport was a two-member seat; in the 1918 general election it was won by two supporters of the Coalition Government, one a Liberal and one a Labour member. After a death and a resignation, a by-election was held for both seats. The seats were again won by two Coalition Government supporters, but this time a Conservative and a Liberal, while a Labour candidate who did not support the government was unsuccessful.

Labour

*Liverpool Scotland by-election, 1929¹, from Irish Nationalist
*Preston by-election, 1929², from the Liberals
*Liverpool West Toxteth by-election, 1924, from the Conservatives

:¹ Uncontested gain from Irish Nationalist.:² Liberal MP defected to Labour and was re-elected as Labour at a by-election the Liberals did not contest.

Principal Opposition loses seats

These records show the rare occasions when the official Opposition failed to hold onto a seat they had won at the previous General election.

Conservative

*Romsey by-election, 2000, lost to the Liberal Democrats
*Roxburgh, Selkirk and Peebles by-election, 1965, lost to the Liberals
*Paddington South by-election, 1930¹, lost to the Empire Free Trade Crusade party
*Liverpool West Toxteth by-election, 1924, lost to Labour

:¹A confused situation, where the victorious Empire Free Trade Crusade candidate was effectively a right-wing unofficial Conservative, who subsequently took the whip and was re-elected as official Conservative candidate.

Labour

*Glasgow Govan by-election, 1988, lost to the SNP
*Greenwich by-election, 1987, lost to the SDP
*Bermondsey by-election, 1983, lost to the Liberals
*Mitcham and Morden by-election, 1982, lost to the Conservatives
*Glasgow Govan by-election, 1973, lost to the SNP
*Lincoln by-election, 1973, lost to Lincoln Democratic Labour
*Rochdale by-election, 1972, lost to the Liberals
*Bristol South-East by-election, 1961¹, awarded to the Conservatives
*Brighouse and Spenborough by-election, 1960, lost to the Conservatives
*Sunderland South by-election, 1953, lost to the Conservatives
*Southwark North by-election, 1927, lost to the Liberals
*Anglesey by-election, 1923², lost to the Liberals
*Woolwich East by-election, 1921, lost to the Coalition Conservatives

:¹seat awarded by Election Court to Conservative runner-up because Labour victor Viscount Stansgate was deemed ineligible.:²Sir Owen Thomas had been elected as Independent Labour, took the whip for a while, before reverting to Independent Labour.

By-election holds overturned at next general election

By-elections usually see the high-water mark of any challenge to the incumbents. On rare occasions a party has failed to overturn an incumbent in the by-election yet has gone on to gain the seat at the subsequent general election.

*South Down by-election, 1986, held by the Ulster Unionists; gained by the Social Democratic and Labour Party in 1987.
*Darlington by-election, 1983, held by Labour; gained by the Conservatives in 1983.
*Dundee East by-election, 1973, held by Labour; gained by the Scottish National Party in February 1974.
*Bolton East by-election, 1960, held by the Conservatives; gained by Labour in 1964.
*New Forest by-election, 1905, held by the Conservatives; gained by the Liberals in 1906.

By-election victors had not contested previous general election

It is unusual for a political party which has not contested a seat at a general election to take it at a subsequent by-election. Many of the parties which have done so were founded after the general election. Independent candidates are not included.

* North Down by-election, 1995, gained by the UK Unionist
* Glasgow Hillhead by-election, 1982, gained by the SDP
* Crosby by-election, 1981, gained by the SDP
* Isle of Ely by-election, 1973, gained by the Liberals
* Lincoln by-election, 1973¹, gained by Lincoln Democratic Labour
* Mid Ulster by-election, 1969, gained by Unity
* Hamilton by-election, 1967, gained by the SNP
* Torrington by-election, 1958, gained by the Liberals
* Chelmsford by-election, 1945, gained by Common Wealth
* Motherwell by-election, 1945, gained by the SNP
* Skipton by-election, 1944, gained by Common Wealth
* Eddisbury by-election, 1943, gained by Common Wealth
* Belfast West by-election, 1943, gained by the Northern Ireland Labour Party
* Ross and Cromarty by-election, 1936, gained by National Labour
* Combined Scottish Universities by-election, 1936, gained by National Labour
* Merthyr by-election, 1934, gained by Labour
* Paddington South by-election, 1930, gained by Empire Free Trade Crusade
* Liverpool Scotland by-election, 1929, gained by Labour
* Kingston-upon-Hull Central by-election, 1929, gained by Labour
* Kirkcaldy by-election, 1921, gained by Labour
* Woolwich East by-election, 1921, gained by the Coalition Conservative

Notes:

¹ the victor was the sitting MP, who had left the Labour party.

Incumbent party did not contest

*North Down by-election, 1995 (party disintegrated before by-election)
*Bristol South East by-election, 1963 (Conservative candidate awarded seat after 1961 by-election had agreed to stand aside, if law changed to permit disqualified Labour candidate to take his seat)
*Cardiff East by-election, 1942 (Conservatives stood aside to allow election of National Government minister)
*City of London by-election, 1940 (Conservatives stood aside to allow election of National Government minister)
*Southampton by-election, 1940 (National Liberals stood aside to allow election of National Government minister)
*Combined Scottish Universities by-election, 1938 (National Labour stood aside to allow election of National Government minister)
*Ross and Cromarty by-election, 1936 (National Liberals stood aside to allow election of National Government minister from National Labour)
*Combined Scottish Universities by-election, 1936 (Conservatives stood aside to allow election of National Government minister from National Labour)
*Liverpool Scotland by-election, 1929 (lone mainland Irish Nationalist was essentially a Labour supporter)
*Preston by-election, 1929 (Liberals acquiesce to William Jowitt becoming Labour's Attorney General)

Losers had been unopposed at previous election

*Paddington South by-election, 1930 Conservative loss, gained by Empire Free Trade Crusade.
*Liverpool Scotland by-election, 1929 Irish Nationalist loss, gained by Labour.¹
*Halifax by-election, 1928 Speaker loss, gained by Labour.²
*Kirkcaldy Burghs by-election, 1921 Coalition Liberal loss, gained by Labour.
*Woolwich East by-election, 1921 Labour loss, gained by Conservative.
*The Wrekin by-election, February 1920 Coalition Liberal loss, gained by Independent.

Notes::¹ the Nationalists did not contest the by-election:² the Speaker had originally been a Liberal MP.

Major party did not run

:The main British parties have generally not stood in seats in Northern Ireland. The by-election exceptions are the Upper Bann by-election, 1990 (Conservatives and continuing SDP) and the North Down by-election, 1995 (Conservatives). Prior to the 1970s the Ulster Unionists were effectively the local Conservatives, whilst the Liberals contested some but not all seats. The Social Democratic and Labour Party has traditionally seen itself as a "sister party" to the British Labour party, and its MPs usually accept the Labour whip in Parliament.

:Neither the Liberal Democrat nor the Labour Party stood candidates in the Haltemprice and Howden by-election, 2008. The by-election was a single-issue election in regards to government security policy, in which the Liberal Democrats supported the Conservative candidate.

:The Conservative Party did not run a candidate in the Bristol South East by-election, 1963, the Carmarthen by-election, 1957, the Paisley by-election, 1948 or the Ogmore by-election, 1946.

:The Labour Party did not run in the City of London by-election, 1945, the Kensington South by-election, 1945 or the Combined English Universities by-election, 1946.

:Prior to 2008, the last by-election without an official Liberal Democrat, Liberal or SDP candidate had been the Newham North East by-election, 1994; the Lib Dems nominated a candidate, but he joined the Labour Party before the election. No official Liberal candidate was nominated was the Glasgow Central by-election, 1980, whilst no Liberal stood in either the Westhoughton by-election, 1973 or the West Bromwich by-election, 1973, both held on 24 May 1973.

:The last Scottish by-elections without official Scottish National Party candidates were the Roxburgh, Selkirk and Peebles by-election, 1965 and the Rutherglen by-election, 1964.

:The last Welsh by-elections without official Welsh Nationalist candidates were the Abertillery by-election, 1950, the Pontypool by-election, 1946 and the Monmouth by-election, 1945.

:The more fluid nature of politics in Northern Ireland makes it harder to define all major parties. In addition many by-elections have not been contested by parties holding other seats in the House of Commons, whether due to agreements with other parties, poor organisation in the constituency or the particular circumstances on the by-election. However for the period since 1981 (which saw the first by-elections in twelve years, during which time several major political realignments had occurred) the main parties are usually considered to be the Democratic Unionist Party, Sinn Féin, the Social Democratic and Labour Party and the Ulster Unionist Party.

::The last by-elections without official Democratic Unionist candidates were the North Down by-election, 1995 and the Upper Bann by-election, 1990. They also did not stand in the twelve seats held by other Unionist parties in the 15 by-elections in 1986.

::The last by-election without official candidates from either Sinn Féin or the Social Democratic and Labour Party was the the North Down by-election, 1995. Both parties also declined to stand in the eleven Unionist majority seats in the 15 by-elections in 1986. The SDLP also did not contest either the April or August 1981 by-elections in Fermanagh and South Tyrone.

::The last by-elections without official Ulster Unionist candidates were North Antrim, East Belfast, Mid Ulster and North Down in the 15 by-elections in 1986.

Victories by minor parties

Victories by independent and minor party candidates since 1945. For a complete list, see the list of UK minor party and independent MPs elected.

*Blaenau Gwent by-election, 2006 - Independent candidate, election agent of the previous incumbent, won with 46.7%.
*North Down by-election, 1995 - UK Unionist Party candidate won with tacit backing of Democratic Unionist Party
*North Down by-election, 1986 - Ulster Popular Unionist Party candidate won without Unionist opposition.
*Fermanagh and South Tyrone by-elections, August and April 1981 - Anti H-Block candidates linked to Sinn Féin won.
*Lincoln by-election, 1973 - Lincoln Democratic Labour Association, incumbent MP held seat in new party colours.
*Mid Ulster by-election, 1969 - Unity candidate won without Irish Nationalist opposition.
*Mid Ulster by-election, 1956 - Independent Unionist candidate won without Unionist opposition.
*Glasgow Bridgeton by-election, 1946 - Independent Labour Party candidate held seat.

Minor parties other strong performance

*Haltemprice and Howden by-election, 2008 with neither Labour nor Liberal Democrat opposition, the Green Party came second with 7.4% of the vote, the English Democrats Party third with 7.2%
*Sedgefield by-election, 2007 British National Party gains 8.9%. Independent candidate gains 6.7%
*Bromley and Chislehurst by-election, 2006 United Kingdom Independence Party (UKIP) gain third place and 8.1%
*Hartlepool by-election, 2004 UKIP gain third place and 10.2%
*Leicester South by-election, 2004 Respect got 12.7%
*Hamilton South by-election, 1999 Scottish Socialist Party gains third place and 9.5%; an Independent candidate campaigning on the future of Hamilton Academicals had fifth place and 5.5%.
*Rotherham by-election, 1994 Monster Raving Loonies' best ever performance with 4.2%.
*Liverpool Walton by-election, 1991 Independent Labour candidate gains third place and 6.5%
*Bermondsey by-election, 1983 Independent Labour candidate gains third place and 7.6%
*Lambeth Central by-election, 1978 National Front gains third place and 6.2%
*Birmingham Stechford by-election, 1977 National Front gains third place and 8.2%
*Birmingham Ladywood by-election, 1977 National Front gains third place and 5.7%
*Walsall North by-election, 1976 Independent candidate gains third place and 11.7%
*Newham South by-election, 1974 National Front gains third place and 11.5%
*West Bromwich by-election, 1973 National Front gains 16.0%
*Rochdale by-election, 1972 Anti-Immigration candidate gains 8.9%
*Southampton Itchen by-election, 1971 National Democrat gains third place and 7.6%
*Liverpool Scotland by-election, 1971 Independent Labour Anti-Abortion candidate gains 10.3%
*Oldham West by-election, 1968 Independent All-party Alliance candidate gains third place and 13.2%.
*Derbyshire West by-election, 1967 Independent candidate gains 5.2%.
*Nuneaton by-election, 1967 Independent All-party Alliance candidate gains 6.3%.
*Rhondda West by-election, 1967 Communist candidate gains third place and 6.8%
*South Dorset by-election, 1962 Anti-Common Market candidate gains 12.3%.
*Bristol South East by-election, 1963 Independent Conservative candidate second with 19.0% (no official Con candidate)
*Swansea East by-election, 1963 Independent candidate gains third place and 8.0%.
*Manchester Moss Side by-election, 1961 Independent cadidate gains 5.2%.
*Blyth by-election, 1960 Independent candidate gains 10.6%.

Miscellaneous notable results

*At the Henley by-election, 2008 the Labour Party finished in fifth place, the worst ranking for the party in its history, and a record low for any government in a UK mainland constituency. The lowest ever for an incumbent government was the Upper Bann by-election, 1990 when the Conservatives came sixth.

*The drop in the Conservative share of the vote, 11.1%, at the Bromley and Chislehurst by-election, 2006 was their worst result in a Conservative-held seat while in opposition since 1930¹. At the same by-election, the Labour Party's fall from second to fourth place was the first time the party had suffered such a reverse in an English seat.

*At the Blaenau Gwent by-election, 2006, held on the same day as Bromley, the Conservative Party's fifth-place ranking equalled the worst-place achieved by a major party in England or Wales, a feat the Conservatives had first achieved in the same seat in the 2005 General Election. The Blaenau victor, Dai Davies was the first independent to hold a seat previously occupied by an independent since Sir C.V.F. Townshend held The Wrekin in 1920.

*The Conservative Party fell from second to fourth place in the Hartlepool by-election, 2004.

*The Labour party fell from second to fourth place in the Ceredigion by-election, 2000.

*In the Hamilton South by-election, 1999, the Liberal Democrats came sixth, equalling the worst ever placing by a major party in the UK.

*The Conservative party fell from third to fourth place in the Liverpool Walton by-election, 1991.

*At the Bootle by-election, 1990 the "continuing" SDP finished seventh out of eight candidates, behind the Monster Raving Loony Party, in a seat parts of which had once been in adjoining Crosby, scene of the party's greatest triumph only eight years previously.

*The Labour Party achieved fourth place in the Richmond (Yorks) by-election, 1989 although this was contrived somewhat by the Social and Liberal Democrats and Social Democratic Party parties running separate candidates.

*The Conservative party fell from second place to fourth place in the Bermondsey by-election, 1983, the first time they had suffered such a reverse since at least 1945.

*At the Walsall North by-election, 1976, the Liberal Party could take only fifth place. Beaten by an independent and a minor party candidate, this was the worst placing for any major party in an English by-election since at least 1945.

*The Conservative party fell from third place to fourth place in the Newham South by-election, 1974, at the time their worst ranking in an English by-election since at least 1945.

*The last time time the Liberals lost a by-election they were defending was at the Carmarthen by-election, 1957, defeated by the former Liberal MP turned Labour candidate, Lady Megan Lloyd-George. The Liberal parliamentary contingent was thus reduced to five MPs, its lowest ever level.

Notes¹Excluding the Westminster, St.George's by-election, 1931 and the Paddington South by-election, 1930, which were essentially intra-Conservative contests, the previous worst result was, ironically, the Bromley by-election, 1930

By-elections having national significance

*Crewe and Nantwich by-election, 2008: A Conservative gain (from Labour in this case) at a by-election for the first time since 1982, and the first time as an opposition party since 1978.
*Wirral South by-election, 1997: A Labour gain on a large swing just weeks before a general election confirmed the move in the party's favour was real.
*Liverpool Walton by-election, 1991: The Militant Tendency opposed a Labour candidate for the first time; their showing led to the decision to organise as a separate party.
*Bootle by-election, May 1990: Abysmal showing of the 'continuing SDP' led to the party being wound up.
*Greenwich by-election, 1987: Defeat of a left-wing Labour candidate demonstrated the party's vulnerability.
*Darlington by-election, 1983: Labour's successful defence of a marginal seat stabilised the party, and secured the position of Leader Michael Foot.
*Crosby by-election, 1981: Victory of the Social Democratic Party in a rock-solid Conservative seat showed the national appeal of the party.
*Fermanagh and South Tyrone by-election, April 1981: Election of Maze prison hunger-striker Bobby Sands demonstrated that nationalist voters could support violent Republican candidates; taken by the Republican movement as a vindication of their stance.
*Hamilton by-election, 1967: Scottish National Party victory massively boosted the prospects of the party.
*Hull North by-election, 1966: Easy Labour victory in a marginal seat demonstrated to Prime Minister Harold Wilson that he would probably win a snap general election.
*Roxburgh, Selkirk and Peebles by-election, 1965: Rare Conservative loss in Opposition leads to resignation of leader Sir Alec Douglas-Home and election of Edward Heath as first democratically-elected Conservative leader.
*Leyton by-election, 1965: Foreign Secretary Patrick Gordon-Walker, who was found the seat after losing Smethwick in 1964, is again defeated; he is forced to resign from the Government.
*Kinross and West Perthshire by-election, 1963: Prime Minister Sir Alec Douglas-Home successfully returned to the House of Commons after disclaiming his Peerage.
*Orpington by-election, 1962: A Liberal gain in a suburban seat led to a national revival for the party.
*Bristol South East by-election, 1961: Incumbent Labour MP Tony Benn re-elected after inheriting a Peerage; the seat was awarded to the defeated Conservative, but the circumstances led to the Peerage Act 1963 allowing hereditary Peerages to be disclaimed.
*Oxford by-election, 1938: After a campaign dominated by appeasement and the Munich agreement, the government candidate won.
*Liverpool Wavertree by-election, 1935: Intervention of Independent Conservative Randolph Churchill, on platform of rearmament and Anti-Indian Home Rule, hands safe seat to Labour on largest ever swing (30%). Indication of hostility to National Government, and Prime Minister Ramsay MacDonald resigns within months.
*Fulham East by-election, 1933: Unexpected Labour gain in a previously safe Conservative constituency, ascribed to pacifism.
*Newport by-election, 1922: Election of an anti-Coalition Conservative in a tight three way contest spurred on Conservative MPs to end their coalition with David Lloyd George.
*Dartford by-election, 1920: massive swing to Labour prefigures the party's eclipse of the Liberals.

Firsts and lasts

*Last election in a university constituency: Combined Scottish Universities by-election, 1946
*Last Conservative gain in a by-election: Crewe and Nantwich by-election, 2008
*Last Labour gain at a by-election: Wirral South by-election, 1997
*First by-election victory by the Social Democratic Party (SDP): Crosby by-election, 1981
*Last by-election victory by the Social Democratic Party (SDP): Greenwich by-election, 1987
*First by-election victory by the Scottish National Party: Motherwell by-election, 1945
*Last unopposed by-election in England, Scotland or Wales: Hemsworth by-election, 1946

ee also

*List of United Kingdom by-elections
*swing (politics)
*Records of members of parliament of the United Kingdom
*UK general election records

References

* 'Who's Who of British MPs: Volume IV, 1945-1979' by Michael Stenton and Stephen Lees (Harvester, Brighton, 1979) ISBN 0-85527-335-6