There are 650 constituencies in the United Kingdom, each electing a single Member of Parliament to the House of Commons at least every five years. Voting last took place in 650 of those constituencies at the United Kingdom general election on 7 May 2015. 330 are held by the Conservative Party, 232 are held by the Labour Party, 56 are held by the Scottish National Party, 8 are held by the Liberal Democrats, 3 are held by Plaid Cymru, 1 is held by UKIP, 1 is held by the Green Party of England and Wales, and there are 18 Northern Ireland seats held by different parties. In addition there is the constituency of the Speaker.