Summary Background Part 1: Voting system for parliamentary elections
16.Elections to the House of Commons are currently run under the “first past the post” system of voting. Under this system, voters place a cross in the box next to the candidate they wish to vote for. The candidate with the greatest number of votes in the constituency wins and is elected as the MP.
17.The Act provides for the question of whether or not the UK should adopt the alternative vote system for future parliamentary elections to be decided in a national referendum.
18.The alternative vote system retains the idea of the single member constituency within a majoritarian voting system. In order to win under the existing ‘first past the post’ system a candidate requires only a plurality of the votes (in other words, to achieve more votes than any of the other candidates). Under the form of the alternative vote system provided for by the Act, candidates must achieve more than 50% of the votes in the count - either at the initial counting stage or, if necessary, at a further counting stage - in order to be elected. The alternative vote also contrasts with the existing electoral system in that voters may express a preference for as many or as few of the candidates on the ballot paper as they wish (they may vote for one candidate only if they wish). However, a key similarity between the two systems is that under both, a single member is elected to represent a single geographic constituency.
19.The key features of the alternative vote system set out in the Act are that:
	Voters rank candidates on the ballot paper in order of preference, using 1, 2, 3 etc.
	Voters may express a preference for as many or as few candidates as they wish. This means that a voter may vote for one candidate only if they wish. This is known as an “optional preferential” system.
	If after the counting of voters’ first preferences, any candidate has more than 50% of the votes at this stage then he or she is declared the winner.
	If no candidate has more than 50% of the votes counted, then there would be a further round of counting. The candidate in last place is eliminated, and each vote originally allocated to the eliminated candidate is reallocated to a remaining candidate according to the next preference expressed on each ballot paper.
	Where there is no next preference given, the ballot paper cannot be reallocated and is no longer counted. If a candidate has more than 50% of the votes left in the count once this reallocation has taken place he or she is elected. If not, then a further round of counting will take place and the candidate now in last place is eliminated and their votes reallocated. This process continues until one candidate has more than 50% of the votes left in the count, and is elected.
20.A number of the key features of the conduct of a parliamentary election using the alternative vote system would broadly be the same as under the existing first past the post system, for example, in terms of the nomination of candidates, the provision of ballot papers and polling stations. However, changes would be required to certain areas of electoral law in order to hold an election under the alternative vote system, in particular the Parliamentary Elections Rules in Schedule 1 to the Representation of the People Act 1983 (“the 1983 Act”) which set out how a parliamentary election is to be conducted (these amendments are set out in section 9 of and Schedule 10 to this Act). Most of these amendments arise from the need to acknowledge the concept of preferential voting and that in the event of multiple preference voting there may be more than one round of counting. Existing rules are based on the idea of a vote that can only ever benefit one candidate and the related notion of a single count.