The United Kingdom general election of 2010 was held on Thursday 6 May 2010 to elect members to the House of Commons. The election took place in 650 constituencies across the United Kingdom under the first-past-the-post system. None of the parties achieved the 326 seats needed for an overall majority. The Labour Party, led by Gordon Brown, won the largest number of votes and seats but were still twenty seats short. This resulted in a hung parliament where no party would be able to command a majority in the House of Commons. This last occurred in the February 1974 election, and only twice since the Second World War.
Coalition talks began immediately between Labour and the Liberal Democrats and lasted for five days. On Tuesday 11 May, Gordon Brown resigned as Prime Minister, and immediately Deputy Leader Harriet Harman became acting leader, successfully pushing for further talks. Brown's resignation was accepted by Queen Elizabeth II, who then invited Harriet Harman to form a government and become Prime Minister. Just after midnight on 12 May, the Liberal Democrats emerged from a meeting of their Parliamentary party and Federal Executive to announce that the coalition deal had been "approved overwhelmingly", sealing a stable coalition government of Labour and the Liberal Democrats.
None of the three main party leaders had previously led a general election campaign, which had not happened since the 1979 election. During the campaign, the three main party leaders engaged in a series of televised debates, the first time ever in a British election. The Liberal Democrats achieved a breakthrough in opinion polls after the first debate in which their leader Nick Clegg was widely seen as the strongest performer. However, on polling day their share of the vote increased by only 1%, and they suffered a net loss of five seats. Still, this was the Liberal Democrats' largest popular vote since the party's creation, and they found themselves in a pivotal role in the formation of the new government.
The share of votes for parties other than Labour or the Conservatives was 35% and was the largest since the 1918 general election. The Green Party of England and Wales won its first ever seat in the Commons, and the Alliance Party of Northern Ireland gained its first representation since 1974.