Boris Johnson’s supporters had been clear that if he won a straight majority in last night’s confidence vote, he would carry on as prime minister. A win, they said, is a win. Except that the history of Tory leadership challenges shows that a win can be anything but.
heresa May, John Major and, most famously, Margaret Thatcher found to their cost that gaining the backing of a majority of their MPs was no guarantee of long-term success.
Instead, it can often signal the beginning of the end.
Boris Johnson knows it, his supporters know it and all Tory MPs know it.
They also know that divided parties do not win elections, which is the main reason that anything other than a resounding win tends not to be enough.
Even such a colossal figure as Mrs Thatcher was unable to survive a less-than-convincing win when she was challenged by Michael Heseltine in 1990.
The ballot had exposed the fact that 45pc of Conservative MPs no longer backed her. She suddenly looked fallible and weakened, and after a series of conversations with Cabinet ministers, many of whom told her they thought she would lose in the second round of voting, she withdrew from the contest just two days later.
Her successor, John Major, faced his own confidence vote three years later, in July 1993, though in his case it was a vote of confidence in the government, called by him, rather than a vote on his leadership among Tory MPs.
After Parliament had been split 50:50 over the social chapter of the Maastricht Treaty, which transformed the European Community into the European Union, Mr Major made clear a second vote on the issue would determine the future of the government.
He won by 339 votes to 299, but his authority never fully recovered. After limping on for another four years Mr Major was defeated by a Labour landslide in 1997.
Theresa May won her own confidence vote in December 2018, by 200 to 117, so had the backing of 63pc of her MPs, but it was not enough. Three months later she announced her intention to resign and by July she was gone.
The ultra-loyal Jacob Rees-Mogg said yesterday morning that even if the prime minister won by a single vote: “One is enough, it’s no good saying that the rules of the party say something and then behind it unofficially there is some other rule that nobody knows and is invented for the purpose.”
Yet Mr Rees-Mogg said after Theresa May won her own confidence vote with the backing of 63pc of MPs that it was a “terrible result” because a third of MPs had voted against her and she “must realise that under all constitutional norms she ought to go and see the queen urgently and resign”.
If the parliamentary party decides that a slim majority is insufficient for Mr Johnson to carry on, he could at any point receive a visit from the “men in grey suits” placing the metaphorical revolver and glass of whiskey on his desk.
Divided parties, as history shows, do not win elections. (© Telegraph Media Group Ltd 2022)