The Labour Party governed the United Kingdom of Great Britain and Northern Ireland from 1974 to 1979. During this period, Harold Wilson and James Callaghan were successively appointed as Prime Minister by Queen Elizabeth II. The end of the Callaghan ministry was presaged by the Winter of Discontent, a period of serious industrial discontent. This was followed by the election of Conservative leader Margaret Thatcher in 1979.

The Labour Party is a political party in the United Kingdom that has been described as an alliance of social democrats, democratic socialists, and trade unionists. The Labour Party sits on the centre-left of the political spectrum. In all general elections since 1922, Labour has been either the governing party or the Official Opposition. There have been six Labour prime ministers and thirteen Labour ministries. Since the 2010 general election, it has been the second-largest UK political party by the number of votes cast, behind the Conservative Party and ahead of the Liberal Democrats. The party holds the annual Labour Party Conference.