Alternative vote plus

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.[1]

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.