John Major's term as the prime minister of the United Kingdom began on 28 November 1990 when he accepted an invitation of Queen Elizabeth II to form a government, succeeding Margaret Thatcher, and ended on 2 May 1997 following the Conservative Party's defeat in the 1997 general election by the Labour Party, led by Tony Blair. While serving as prime minister, Major also served as the first lord of the treasury, the minister for the civil service and the Leader of the Conservative Party.