For a time the Tory daggers remained sheathed, and it seemed just conceivable that Theresa May’s backbenchers would refrain from turning on her after her belated discovery that Jeremy Corbyn, far from being a Marxist revolutionary whom all decent people wish to consign to outer darkness, is a fit and proper person with whom to negotiate our nation’s future.

Corbyn revelled in his statesmanlike new persona. He welcomed “her commitment to compromise to resolve the Brexit deadlock”, and proceeded to praise the achievements of Tony Blair and Gordon Brown.

According to Corbyn, the last Labour Government halved child poverty, halved homelessness and lifted two million pensioners out of poverty.

He accused May of denying free television licences to the over-75s. This campaigning was an unwelcome reminder of how formidable an opponent Corbyn might be if a general election were to be called.

This Leader of the Opposition will stop at nothing. In his restless quest for power he is prepared to present himself as a Blairite.

In vain the Prime Minister protested, “I didn’t realise he was such a fan of the last Labour Government.” Corbyn had shown everyone that he is a better campaigner than she is.

The Speaker called Nigel Adams, who had just resigned from the Government in protest at May’s decision to “cook up” a deal “with a Marxist who has never once in his life put British interests first”.

But Adams asked the Prime Minister “to put her weight behind the campaign for step-free access to Selby railway station”.

This gentle request occasioned incredulous laughter. Perhaps, after all, she was going to get away with it. Suella Braverman, who resigned as a Brexit minister in November in protest at May’s policy, asked a question about mental health.

But then David Jones, a former Cabinet minister and stern unbending Brexiteer, rose and asked: “Does it remain the position of the Prime Minister that the Leader of the Opposition is not fit to govern?”

That was the first dagger to be plunged into her, and she sounded rattled, though she rallied a bit as she reminded the House of Corbyn’s lamentable reaction to the Russian attack in Salisbury.

Lee Rowley (Con, North East Derbyshire) wanted to know what now qualifies Corbyn for involvement in Brexit, given that the Prime Minister had only last week called him “the biggest threat to our standing in the world”.

Caroline Johnson (Con, Sleaford & North Hykeham) remarked that she had voted for May’s deal, and asked another tough question: “If it comes to the point when we have to balance the risk of a no-deal Brexit versus the risk of letting down the country and ushering in a Marxist, anti-semite-led government, what does she think at that point is the lowest risk?”

Julian Lewis (Con, New Forest East) reminded the Prime Minister that she “repeatedly told us no deal is better than a bad deal”, and called on her to stop blocking “a WTO Brexit”.

Perhaps most wounding of all, Nigel Evans (Con, Ribble Valley) said that if the European Union will only grant her a long Brexit extension, she must declare: “No! No! No!” – words used by Margaret Thatcher.

May was by now starting to look like a pin cushion, stabbed repeatedly in broad daylight by her own backbenchers before a full House. One was reminded of the Agatha Christie story where everyone turns out to be guilty of committing the murder.

Nick Boles, who left the Conservative Party on Monday night, now describes himself as an Independent Progressive Conservative and was sitting between the Liberal Democrats and the Welsh Nationalists, managed at the very end of PMQs to catch the Speaker’s eye.

Boles congratulated her on her “late conversion to compromise”, and urged her to ditch “the red lines which have bedevilled the Brexit negotiations so far”.

One could not help thinking Corbyn, in his Marxist persona, might rather like the idea of keeping to a red line.

But May avoided answering Boles’s question. She didn’t look, in her person, as tired as she has at some points during this process. There were flashes of perkiness from her.

For at least the whole situation is now highly fluid, and at the cost of enraging her own backbenchers, she sees a chance of getting her deal through the House.

She picked up a reference to her hero, Geoffrey Boycott, and remarked: “He stayed at the crease, he kept going and he got his century in the end.”