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
Margaret Thatcher on and fight to win" the second ballot, but consultation with her Cabinet persuaded her to withdraw. After holding an audience with the Queen, calling other world leaders, and making one final Commons speech, on 28 November she left Downing Street in tears. She reportedly regarded her ousting as a betrayal. Her resignation was a shock to many outside Britain, with foreign observers such as Henry Kissinger and Gorbachev privately expressing consternation. Thatcher was replaced as Prime Minister and party leader by Chancellor John Major, who prevailed over Heseltine in the subsequent ballot. Major oversaw an upturn in Conservative support