Thatcher ousted by her own party (1990)
Margaret Thatcher, an election-winning Conservative prime minister, was forced out by her own MPs after a leadership challenge. She resigned rather than lose a second-round vote, and John Major replaced her without a general election.
Major took office and led the Conservatives to a narrow 1992 election win.
The episode showed UK parties will remove a sitting prime minister mid-term when MPs judge them an electoral liability.
Like Starmer, Thatcher lost the confidence of her own MPs and chose to step aside rather than fight a losing internal battle.
