In the sort-of three party system in use in the UK, it’s become quite rare for an MP to actually secure the majority of the vote in a constituency. Under alternative vote (often discussed in the US as “instant runoff voting”) people rank candidates in order when nobody gets a majority, you take the candidate who finished last, strike his name, and then redistribute his votes to his supporters’ second-place choices. Then you keep on trucking along until someone has a majority. The core supporters of AV have been Liberal Democrats (who are badly disadvantaged by the status quo voting system) but the Lib Dems have managed to alienate tons of people by joining David Cameron’s coalition, which, somewhat ironically, they had to do in order to get the AV referendum done.
Alternate Vote And The Oscars