1990 Conservative Party (UK) leadership election 1990 Conservative Party (UK) leadership election The 1990 Conservative Party leadership election in the United Kingdom took place on 20 November 1990 following the decision of Michael Heseltine, former Defence and Environment Secretary, to challenge Margaret Thatcher, the incumbent Prime Minister, for leadership of the Conservative Party. Thatcher failed to win outright under the terms of the election in the first ballot, and was persuaded to withdraw from the second round of voting. She announced her resignation on the morning of 22 November 1990, ending more than 15 years as Conservative leader and 11 years as Prime Minister. Discontent with
1990 Conservative Party (UK) leadership election opposition benches and reinforced the change in general perception of Thatcher from the "Iron Lady" to a divisive and confrontational figure. The next morning, 14 November, Heseltine announced that he would challenge her for the leadership of the party. The rules for Conservative leadership contests had been introduced for the first such election, in 1965, and modified in 1975, the occasion of Thatcher's own victory over the incumbent leader Edward Heath. There would be a series of ballots of Conservative MPs, conducted by the 1922 Committee, with that committee's chairman, Cranley Onslow, as Returning Officer. To win in the first