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
Third Thatcher ministry European Community. On 14 November, former cabinet minister Michael Heseltine challenged Thatcher's leadership. Thatcher polled higher than him in the first round of the leadership contest, but failed to gain an outright victory in the first round of voting. Within minutes of the result being announced, Thatcher informed reporters that she intended to let her name go forward for the second ballot. However, on 22 November, before a second round of the contest could take place, Margaret Thatcher announced her resignation as Prime Minister and Leader of the Conservative Party after more than 11 years, explaining that she was resigning