From the archives;
'22 November 1990 Thatcher quits as prime minister
Margaret Thatcher is to stand down as prime minister after her Cabinet refused to back her in a second round of leadership elections.
She will remain in office until a successor is elected, but will not continue to fight Michael Heseltine for the Conservative Party leadership.
The former secretary of state for the environment threw down the gauntlet after a string of serious disputes over Britain's involvement in the European Union.
The prime minister said pressure from colleagues had forced her to conclude that party unity and the prospect of victory in the next general election would be better served if she stepped down.
BBC News Time's up, bLiar, resign!!