Third Thatcher ministry to make way for a leader more likely to win the next general election. Her successor was the Chancellor of the Exchequer John Major, who was elected on 27 November 1990, and who at 47 became the youngest Conservative Prime Minister of the 20th century. <section begin="June 1987 to July 1989" /> <section begin="July 1989 to November 1990" /> Members of the Cabinet are in bold face. Third Thatcher ministry Margaret Thatcher was Prime Minister of the United Kingdom from 4 May 1979 to 28 November 1990, during which time she led a Conservative government. She was the first woman
Premiership of Margaret Thatcher her opposition to greater economic integration into the European Community. She also alienated many Conservative voters and Members of Parliament with the imposition of the local poll tax. As her support fell away, she was challenged for the party leadership and persuaded by her Cabinet to withdraw from the second round of voting, ending her eleven-year tenure as Prime Minister. Though she remains a domestically polarising figure, historians and political scientists generally rank Thatcher as an above-average Prime Minister. Biographer John Campbell reports that in July 1978 when asked by a Labour MP in Commons what she meant by socialism: