Referendum on the voting system used to elect MPs to the House of Commons

Referendum on electing MPs

The first UK-wide referendum since 1975 was held on 5 May 2011 on whether the system used to elect MPs to the House of Commons should be changed.

Referendum question

The Parliamentary Voting Systems and Constituencies Act 2011 provided for a UK-wide referendum to be held on 5 May 2011 on changing the voting system for electing MPs to the House of Commons.

The following question was on the referendum ballot paper:

"At present, the UK uses the 'first past the post' system to elect MPs to the House of Commons. Should the 'alternative vote' system be used instead?"

The result of the referendum was:

  • Yes: 32 per cent
  • No: 68 per cent

The first past the post system continues to be used to elect MPs to the House of Commons.

What are the two voting systems in the referendum question?

First past the post

Under first past the post, a voter puts a cross (X) next to their preferred candidate on a ballot paper. Ballot papers are then counted and the candidate that has received the most votes is elected.

Alternative Vote

Under the Alternative Vote, a voter ranks candidates in order of preference by marking 1, 2, 3, and so on, next to the names of candidates on a ballot paper. A voter can rank as many or as few candidates as they like or just vote for one candidate.

Ballot papers are then counted by using the first preference votes (i.e. those with a number 1 marked next to their name). If a candidate receives more than 50 per cent of the first preference votes then they are elected.

If no candidate reaches this 50 per cent threshold, then the candidate with the fewest first preference votes is eliminated. Their second preference votes are then reallocated to the remaining candidates. If after this stage one candidate has more votes than the other remaining candidates put together, that candidate is elected.

If not, the process of elimination and reallocation of preference votes is repeated until one candidate has more votes than the other remaining candidates put together, and is then elected.

Further information

The Electoral Commission published their report on the May 2011 referendum in October 2011.

Related information

Find out how the House of Commons, devolved assemblies and mayors in the UK are elected using different voting systems.

Parliamentary Voting Systems and Constituencies Act 2011

Related information

What is a referendum?

A referendum is a method of referring a question or set of questions to the entire electorate directly.

Voting systems in the UK

Find out what voting systems are used to elect the House of Commons, Scottish Parliament, Welsh Assembly, Northern Ireland Assembly, European Parliament and local authorities in the UK.

1975 referendum

The last UK-wide referendum took place on 5 June 1975. The referendum question asked ‘Do you think the UK should stay in the European Community (Common Market)?’. A majority voted yes (67 per cent).

Electoral Commission

The Electoral Commission is an independent body, accountable directly to the UK Parliament, that regulates elections in the UK and promotes voter awareness.