David Cameron's term as the prime minister of the United Kingdom began on 11 May 2010, when he accepted an invitation of Queen Elizabeth II to form a government, succeeding Gordon Brown of the Labour Party, and ended on 13 July 2016 upon his resignation following the 2016 referendum that favoured Brexit, which he had opposed. While serving as prime minister, Cameron also served as the first lord of the treasury, minister for the civil service and leader of the Conservative Party.