LONDON -- British Prime Minister Boris Johnson may have survived a no-confidence vote, but his grip on power is far from secure.
Many compare his position to that of his predecessor Theresa May, who won a similar vote by a larger margin than Johnson but was nonetheless ousted six months later.
"The history for prime ministers who survive confidence votes isn't that great," said Tim Bale, professor of politics at Queen Mary University of London.
A look at how previous Conservative prime ministers fared after leadership challenges against them:
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MARGARET THATCHER
Thatcher survived a first leadership challenge in 1989, but a second one the next year spelled her downfall.
In 1989, a little-known lawmaker, Anthony Meyer, launched a challenge against Thatcher, who had been reelected as party leader unopposed every year since 1974. Thatcher won comfortably by 314 votes to 33 but, counting deliberately spoiled ballot papers, about 60 had failed to endorse her -- an early indication that her position was shaky.
The next year, former defense secretary Michael Heseltine mounted his own bid to wrest leadership from Thatcher amid serious divisions within the Conservatives.
Thatcher won 204 votes to Heseltine's 152 in the first round of the leadership election, but the margin wasn't enough to defeat him outright, forcing a second round.
The "Iron Lady" resigned two days later, and Conservative lawmakers subsequently elected John Major as her successor in a second ballot.
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JOHN MAJOR
Major took over as Thatcher's handpicked successor in December 1990.
In June 1995, Major resigned as party leader to force a leadership contest against himself, challenging his party to "put up or shut up" in a bid to quell a persistent group of critics within the Conservative ranks opposed to Britain's closer integration with the EU.
Major secured a majority of votes in a Conservative leadership contest against rival John Redwood, but a third of the party either voted against him, spoiled their ballot papers or abstained.
Major clung onto power for almost two more years, until the Conservatives lost the 1997 general election in a landslide victory for Labour's Tony Blair.
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THERESA MAY
May, who became Britain's second female prime minister in July 2016, faced severe pressure throughout her tenure over her repeated but ultimately unsuccessful attempts to take Britain out of the European Union.
In December 2018, 48 Conservative lawmakers furious with her Brexit policy triggered a no-confidence vote in her. She won by 200 votes to 117, but the results meant she lost the support of one-third of her lawmakers.
Opposition continued to buffet her leadership and May fought in vain to get lawmakers' backing to implement the Brexit deal she struck with the EU. Parliament rejected her plan three times, and even previously loyal members of her Cabinet openly criticized her bill.
May was forced to step down in May 2019, saying "it will always remain a matter of deep regret for me" to fail to deliver Brexit.
Bale, the politics professor, believes Johnson is different from Thatcher and May and will not resign voluntarily.
"Many of Boris Johnson's opponents would say that the only interest he has at heart is his own continuation in the job. So he really will have to be kicked out of Downing Street" by lawmakers, Bale said.
