|Part of the Politics series|
The alternative vote plus (AV+), or alternative vote top-up, is a semi-proportional voting system. AV+ was devised by the 1998 Jenkins Commission which first proposed the idea as a system that could be used for elections to the Parliament of the United Kingdom.
As the name suggests, AV+ is an Additional Member System which works in two parts: the 'AV' part and the 'plus' part. As in the alternative vote system, candidates are ranked numerically in order of preference. The important difference is that an additional group of members would be elected through regional party lists to ensure a degree of proportionality; in typical proposals, these members are 15–20% of the whole body. More specifically, each voter would get a second vote to elect a county or regional-level representative from a list of candidates of more than one person per party. The number of votes cast in this vote would decide how many representatives from that county or region would go on to parliament. In systems with an electoral threshold on regional seats, votes are transferred in order of voters' numerical preference until it puts a party above the threshold, or reaches a party already above.
Then Prime Minister Tony Blair issued a statement, saying that the report "makes a well-argued and powerful case for the system it recommends" and that "it is very much a modification of the existing Westminster system, rather than any full blown PR system as practised in other countries." He also praised Lord Jenkins for his work and gave the recommendations a cautious welcome, pointing out in particular that change would help address the "complete absence of Conservative representation in Scotland", a reference to the then most recent election in which the Conservatives failed to win a single seat in Scotland, despite winning 17.5% of the Scottish vote.
However, leading figures in the Cabinet at the time (e.g. Home Secretary Jack Straw, Deputy Prime Minister John Prescott, Chancellor Gordon Brown, and Margaret Beckett) and the Labour NEC, all strongly opposed reform of the voting system, and blocked the chance of change at that time.
The report was welcomed by the Liberal Democrats and the SNP, although at the time the Liberal Democrats remained largely committed to STV, but preferred AV+ to First Past the Post. The report was heavily criticised by the Conservative party, with leader William Hague branding its proposals "a dog's breakfast".
In a May 2009 article in The Times, Health Secretary Alan Johnson called for a referendum on the adoption of this system as part of the response to the 2009 parliamentary expenses scandal. In this piece he praised the system as "an elegant solution". David Cameron, Leader of the Conservative Party, declared on May 26 that his party did not support the AV+ system, or any other form of proportional representation, as it would end up choosing a government "on the basis of secret backroom deals".
In June 2009, it was reported by the BBC that the Prime Minister, Gordon Brown, was considering changing the electoral system as part of a package of constitutional reform. In February 2010, the Labour government under Gordon Brown offered a Commons vote on a referendum for an alternative vote system, possibly manoeuvering for political positioning in case of a hung parliament following the general election on May 6. In a BBC interview on Election Night 2010, Home Secretary Alan Johnson suggested he would like to see the AV+ system introduced if a deal with the Liberal Democrats became necessary.
A national referendum on the Alternative Vote system was granted as part of the Conservative – Liberal Democrat coalition agreement, but not AV+. The Jenkins Commission rejected plain AV on the basis that it did little to relieve disproportionality, but favoured it over first-past-the-post as the basis for AV+.
The referendum on AV was held on May 5, 2011 and rejected the proposed AV voting system in favour of retaining First Past the Post.
AV+ has several properties which may be considered advantages or disadvantages based on ones views on how an electoral system should work and what effects it should produce. Common arguments in favour or against are similar to those relating to its component systems, AV and AMS.