1990 Margaret Thatcher announced her resignation as British prime minister after a split
occurred in the ranks of the Conservative Party.
The implementation of a poll tax in 1989 produced outbreaks of street violence and alarmed the Conservative rank-and-file, who feared that Thatcher could not lead the party to a fourth consecutive term. Spurred by public disapproval of the poll tax and Thatcher’s increasingly strident tone, Conservative members of Parliament moved against her in November 1990.
Although she defeated her most senior opponent, former defense minister Michael Heseltine, by 204 votes to Heseltine’s 152, her total fell four votes short of the necessary majority plus 15 percent, and she decided not to contest the election in a second ballot.
On November 22 she announced her resignation as Conservative Party leader and prime minister, paving the way for her replacement by John Major six days later.