Conversely, in February 1974, the Conservatives beat Labour by more than 200,000 votes, but had four fewer seats; Harold Wilson was able to form a minority government after Edward Heath's attempt to form a coalition with the Liberals had failed. It was after this election that discontent with the system started to grow.

What are the alternatives?

The Alternative Vote (AV) is a system where the voter has the chance to rank the candidates in order of preference.

The voter puts a '1' by their first choice a '2' by their second choice, and so on, until they no longer wish to express any further preferences or run out of candidates.

Candidates are elected outright if they gain more than half of the first preference votes. If not, the candidate who lost (the one with least first preferences) is eliminated and their votes are redistributed according to the second (or next available) preference marked on the ballot paper.

This process continues until one candidate has half of the votes and is elected. A referendum in 2011 saw UK voters reject the idea of replacing First Past The Post with the Alternative Voting system.