Supplementary vote

• The supplementary vote is an example of a majoritarian system
• Supplementary Vote was historically used to elect mayors and police commissioners, and is usually used when electing a single person as opposed to a party
• In SV systems, voters select a first and second (optional) preference. If a candidate wins a majority of the first preference they are elected, however, if no candidate wins the first preference majority then all the candidates bar the top two candidates are removed from the vote. The second preference votes cast for the removed candidates are then added to the votes the top two candidates received in order to decide on the winner.
• Under the supplementary vote system, candidates are encouraged to work harder to gain a majority
• It can be argued that supplementary voting will lead to less safe seats as there is more choice than FPTP.
• Under supplementary voting, coalitions can be formed when no majority is gained
• The supplementary vote means politicians will need a wider support base than FPTP due to the second preference option
• 'The Supplementary Vote stops candidates winning on low levels of support, but doesn't need them to get half the vote' - Electoral Reform Society
• Since Supplementary voting began being used to elect the Mayor of London, 2016 was the only year a mayor won more than 50% of the total non-transferable ballots.
• The Supplementary vote is no longer used in mayoral and PCC elections as part of the Elections Act (2022).