Used:House of commons and England and Wales local elections
-Constituency system. There are 646 parliamentary constituencies in the UK, all of roughly equal size
Method: Single candidate selected on a ballot paper. Reflects the idea of 'one person, one vote'. The winning candidate has to be the first one to reach a majority of the votes
-Candidate A= 30000 votes
-Candidate B= 22000 votes -candidate A would win with on 38% majority
-Candidate C= 26000 votes
-Each constituency returns a single candidate, often resulting in the 'winner takes all effect' and hopefully creates a single party government, however it sometimes (like now) causes a hung parliament and consequently a coalition
Single transferable vote
Used: Northern Ireland Assembly, in northern island and scotland local elections and in northern ireland for EU parliament
-Multimember constituencies are used. In the Norther Ireland Assembly, 18 constituencies are used and each constituency returns 6 members.
Method: Electors rank candidates in order of preference and candidates are elected if they achieve a quota of votes. The droop formula is used to calculate quota. Votes are then counted according to first preference first. If quota is achieved additiona votes are added according to second or subsequent preferences. If there still isn't a majority, the losing prty drops out and allocates all votes to other parties
Advantages: potentially highly proportional, judged on personal strengths, constituents can choose between representatives
Disadvantages: proportionality varies, single-party governemtn is unlikely, encourage competition between members of the same party
Additional Members System (AMS)
used: Scottish parliament, Welsh Assembly, Greater London Assembly
-Hybrid system meaning it contains a mixture of both cpnstituency and party-list elements
Method: Between 56 and 66% of seats are filled using 'fptp'. The rest of the seats are filled using a 'closed' party list sytem.The electorate cast 2 votes, one for the party and one for a candidate. These votes are then used to 'top up' the existing votes using the D'Hondt method, in order to achieve the most proportional outcome.
Advantages: Balances the need for constituency representation against the need for electoral fairness. Keeps alive the possibility of single-party government. Allows voters to make wider and more considered choices.
Disadvantages: Reduces the likelihood of high levels of proportinality. Creates confusion by having 2 classes of representative. Because o the larger size of constituencies and because a large number hacve no duties it is less effective than fptp.