Ever since the prime minister’s dismal victory in Monday’s no confidence vote the pundits have been comparing his tally to that of the ultimately doomed Conservative leaders who survived comparable votes.

That 59 per cent of Conservative MPs backed him in the secret ballot compares unfavourably with the 63 per cent who stuck with Theresa May in December 2018 (she resigned seven months later) and the 66 per cent who preferred to shut up rather than put up against John Major when he called a confidence vote in himself in 1995. 

The Iron Lady had set herself against the march of progress

Johnson outperformed Margaret Thatcher in 1990 (she won the support of 55 per cent of her MPs, although because there were abstentions, the same proportion, 41 per cent, voted against her as against Johnson). Marginally outperforming a prime minister who resigned within days of that first round ballot cannot be considered an achievement.

One problem with these historical comparisons is that there are not enough of them from which to build a clear precedent. What is more, each involved different personalities in different circumstances. Shorn of context, the voting statistics tell us only so much. It was how each leader was unable to overcome all-encompassing jeopardies that determined what happened next.

In 1990, Thatcher’s rebels brought her down over two issues about which she could offer them no prospect of a satisfactory resolution. Beyond a little light tinkering, she would not abandon the poll tax, despite its obvious flaws and nationwide unpopularity. For most of her parliamentary opponents, particularly and most dangerously in the Cabinet, her increasingly voluble Euroscepticism was intolerable. As they saw it, Europe was uniting and the Exchange Rate Mechanism was the medicine the British economy needed. Simply, the Iron Lady had set herself against the march of progress. She had no means of escaping this prevailing groupthink. She had lost the support of her Cabinet.

In 1995, Major could have given satisfaction to one wing of the party by ruling out abolishing sterling. But only at the cost of losing the sympathy of his Cabinet’s “big hitters” (particularly Ken Clarke and Michael Heseltine) upon whom he depended for his shaky authority. Hence, he persisted with the untenable “negotiate and decide” policy on the euro — going into a general election by not revealing whether or not he was planning to scrap the electorate’s currency. None of Johnson’s policies, whatever they may be this week or next, is intrinsically this fantastical.

The weather-makers in the Cabinet have not moved against him

As for Theresa May, it is not clear that the December 2018 vote on her future offers much insight into Johnson’s chances. Her tactic for survival then was a pledge that if MPs voted to keep her for the moment she would stand down before the next election. She then proceeded to demonstrate she was incapable of getting any Brexit deal through Parliament, nullifying the only reason to keep her in Downing Street. By contrast, Johnson’s shtick is the reverse of a promise to stand down before the next election. On the contrary, he maintains that he’s the only man with the heft and brio to win the next election.

The other factor to weigh is Cabinet support. By the time she met the verdict of her MPs, Thatcher was facing open dissent from her senior ministers, and had endured the bruising resignations of her chancellor, Nigel Lawson, and deputy-prime minister and leader of the House, Sir Geoffrey Howe. Both men blamed her actions for their decision to quit. 

May chaired the least respectful Cabinet in British history. Scarcely had a Cabinet meeting concluded than its participants were actively briefing journalists against both her and one another. May’s government set records for ministerial departures (51), including 12 resignations from the Cabinet — including her foreign secretary (B Johnson).

What is remarkable about Johnson’s recent withering popularity is that it has, as yet, produced only minor ministerial resignations. The weather-makers in the Cabinet have not moved against him. That may be because they are less certain of their place in the world without his patronage. But it also reflects that there is no single overwhelming issue of policy that is a resigning issue for them.

Johnson’s survival, for the moment, depends in part on his failure to take a strong stand on a policy decision that his senior Cabinet colleagues regard as a resignation issue. But constructive ambiguity only takes a government so far.