Underhang seat

Underhang seats can arise in elections under any proportional representation (PR) electoral system, when a party is entitled to more seats according to party votes than it has put candidates forward for.

Under list PR systems, parties receive a number of seats based upon the number of votes they received. If a party does not have enough people to fill its vacancies, there is an underhang. For example, if a party wins enough votes for ten seats, but only have seven people nominated on its list, then there is an underhang of three seats.

Parties with underhangs usually are not entitled to retroactively add to their list, and lose the potential seats within the legislature represented by the underhang. This is the process used in New Zealand. For instance, in the , if the 99 MP Party (whose stated manifesto is to reduce the size of parliament) had received five percent of the vote, they would have been entitled to six seats within the 120 seat House of Representatives. But, as they only had two people on their list, they would have only filled two seats. The House would have thus shrunk by four MPs. Since, in fact, the party actually received only 0.03% of the vote, this eventuality was avoided.

Another method to dealing with underhangs is to allow the party to nominate people to become MPs.

Parties will, however, aim to avoid the problem by having a substantially larger list than they would hope to win as seats, and underhang is presumably a rare occurrence.

See also

*Overhang seat