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
Historical rankings of Prime Ministers of the United Kingdom using a 0 to 10 scale, where 0 meant highly unsuccessful and 10 meant highly successful. Overall, MPs rated Margaret Thatcher as the most successful post-war Prime Minister, just ahead of Clement Attlee. With the exception of Edward Heath, who was judged more favourably by Labour MPs than by Conservatives, evaluations were split along party lines: Tory MPs tended to consider Conservative prime ministers to be more successful than did Labour MPs, and Labour MPs generally gave Labour prime ministers higher scores than did Conservative MPs. In October 2016 the University of Leeds, in conjunction with Woodnewton Associates, surveyed 82