May will be out of a job in weeks and Johnson has said he’s running – are the stars aligning for a Boris premiership?

But even if he is to win the much-coveted prize, who knows if there will be a Tory party left to lead

When Boris Johnson was asked today about the Conservative leadership, he said: “Of course I’m going to go for it.” What he meant, according to one of his leadership campaign team, was that there is no vacancy at the moment, but that he would be a candidate when there was.

Moments later Sir Graham Brady, chair of the 1922 Committee of Tory backbenchers, came as close as he could to confirming that there would be a vacancy in about three weeks’ time.

Sir Graham issued a statement after an hour-long meeting between his executive and Theresa May, in which they held back from sacking her on the spot – on condition that she sack herself after the vote on the second reading of the withdrawal agreement bill in the first week of June: “We have agreed that she and I will meet following the second reading of the bill to agree a timetable for the election of a new leader of the Conservative and Unionist Party.”

She has fended them off for as long as she can. It would seem that a majority of Conservative MPs have decided that her failure to deliver Brexit is so abject that it is time for desperate measures. Many of them have no time for Johnson, but they console themselves that funny things can happen in leadership elections.

In any case, some of them think the Tory party faces utter destruction. Crispin Blunt is the only one who has gone public, but many MPs think Nigel Farage’s Brexit Party could replace the Tories unless they take emergency action. Some of them remember John Redwood’s leadership slogan from 1995: “No change, no chance.”

So the mood has shifted. Even if Boris Johnson wins, the party has to change leader.

May will be allowed one last chance to get her Brexit deal through parliament, with a vote next month, possibly on Friday 7 June. Labour will vote against, as Emily Thornberry, the shadow foreign secretary, confirmed yesterday – unless the cross-party talks produce an agreement before then, which they won’t. Even if Theresa May gave Jeremy Corbyn everything he says he wants – a permanent customs union with a red Labour flag on it – he would say he couldn’t support it because a new prime minister could come in and tear it up.

Then the leadership contest, raging undeclared for months, will begin in public. Johnson’s prospects nudged up a little in the betting markets this morning. He now has a 25 per cent chance of becoming the next permanent Tory leader – which is surprisingly low, reflecting the uncertainty of these things, based on what happened last time.

Who can forget where they were when they heard that Michael Gove, on the morning of Johnson’s leadership launch, declared himself a candidate and said, in effect, that his ally was unsuited to high office?

This time, Johnson is resolute and prepared for the knocks. “Being outside the system has made him more gung-ho,” according to “someone who knows him well” who spoke to James Forsyth, political editor of The Spectator (former editor: Boris Johnson).

The biggest challenge, though, is not winning but ensuring there is a Tory party left to lead. Whether the new leader and prime minister is Johnson or the traditional surprise candidate, they will face the problem that the Tory party is finished if it fails to deliver Brexit.

All the candidates are likely to promise to renegotiate the withdrawal agreement and to leave without a deal if the EU refuses to change it. But the House of Commons has proved that it won’t allow a no-deal exit, so these candidates might have to campaign with fellow MPs and party members on a promise to fight a general election on a no-deal platform.

Is this really a good idea while Nigel Farage is rampant, and while Labour can rely, in a general election, on an anti-austerity, change-the-Brexit-subject message?

It is a measure of the desperation of the Tory party that it is prepared to risk putting Jeremy Corbyn in No 10 to try to save itself from the wreckage of its Brexit hopes.