Never has the Prime Minister been more desperate for a deal.  And it is still possible that she may get one that can pass the Commons by March 29.  That would surely require changes to the text of the Withdrawal Agreement itself in relation to the backstop.

But today, it is reported that she will ask the Cabinet this morning to support moves that would bring about a delay to the implementation of Article 50, and the seeking of an extension – thereby ruling out a No Deal Brexit on March 29.  It is difficult to see why this would make the EU more likely to agree a deal.  Admittedly, it would perhaps still prefer to strike a bargain with Theresa May before March 29 rather than seek one with her afterwards. For in the event of an extension, the manoeuvres will be complex but the politics clear: a quantum of power will pass from the executive to the legislature.  That would be constitutional unknown country, and the EU might be wary of it.

However, it is possible that a delay would harm such a deal rather than help it.  Why should the EU continue to work with a weak – and from its point of view inconstant and untrustworthy – government?  Wouldn’t it be better off agreeing a very long extension, and waiting for Brexit to unravel completely, as MPs slowly come round to holding a second referendum – as Jeremy Corbyn is being manoeuvered into doing?  Or else watch the Commons settle instead for some form of Nick Boles’ Norway Plus plan, which offers a softer form of Brexit than May’s deal?

At any rate, the most pressing consequence of any such U-turn by May would be internal to her Government and leadership rather than external to the EU and the negotiation.  If she proposes ruling out a No Deal Brexit on March 29, or seeking an extension, or both, she will do so primarily to head off Amber Rudd and company voting for the Letwin-Cooper amendment tomorrow.  In which case, it will be proven that she is unwilling to sack them if they do so.  In which event, too, it will be clear that she has lost what control was left to her of her Cabinet and Ministers: Claire Perry and Margot James join the open rebellion this morning.

A moral of such a story will be that Brexit-backing Ministers resign from Cabinet when they disagree with Government policy: David Davis, Boris Johnson, Esther McVey, Dominic Raab.  And that its Remain-leaning Ministers do not.  Instead, they stay – and give the Prime Minister two fingers.  But there would be a deeper lesson, and one that is painful to grasp.  It is that nothing than May says about her Brexit policy can be trusted.  Only yesterday, she was insisting that “an extension to Article 50…doesn’t deliver a decision in parliament”.  The words of Gordon Brown to Tony Blair echo in our ears: “there is nothing that you could say to me now that I could ever believe”.

As recently as February 7, she was insisting that “I am going to deliver Brexit, I am going to deliver on time”.  But a U-turn on extension would only be the latest of a long series – over seeking a general election in 2017; controlling migration during transition; extending transition; putting her deal to the Commons in December; opposing a regulatory border in the Irish Sea. (Check out her “Road to Brexit”  video where she warned that this would keep Northern Ireland in “…parts of the Single Market. That would would break up the UK economically, and creating new barriers to our own internal market”.)

It would be pointless to list them all.  May’s loss of authority is understood by everyone from Cabinet members through Conservative MPs through party members to voters and our readers.  It may just be that the claims of an about-turn from the Prime Minister on extension are mistaken (though for better or worse we have been predicting the move since the New Year).  But assuming that they are correct, what should happen next?  Obviously, the coalition of Cabinet ministers that stretches from Jeremy Hunt and Sajid Javid through to Andrea Leadsom and Penny Mordaunt should contest the policy this morning and mull their positions.

But as Esther McVey discovered last year, there are no votes in Cabinet.  The Prime Minister sums up and controls the minutes.  And resignations would not in themselves help to deliver Brexit on time.  Indeed, they would probably have the opposite effect, as these harder Brexiteers were disproportionately replaced by softer ones.  There is no prospect of a leadership change.  Nor is one practicable scarcely more than a month from March 29.  Even a general election might not deliver an improvement.  Rather, one couldn’t rule out a Marxist Government emerging from it.  And if it did deliver a Conservative majority, the divisions within the Parliamentary Party would endure.

The only advice we can offer to Tory MPs is that if a deal is eventually placed before them which sorts the backstop problem, then they should vote for it.  If it doesn’t, then they shouldn’t.  And either way, they should vote against any motion proposing extension.  For all our reservations about No Deal, we recall the Conservative Manifesto’s pledge: No Deal is better than a bad deal.  Extension or no extension, Tory MPs should battle for that commitment in the TV studios and on Twitter and in the Chamber and the lobbies.  They should fight for it by every means available, save one: namely, not backing the Government in a vote of confidence, thus risking a Marxist Government under Corbyn and John McDonnell (and a second referendum in any event).

All else they can do is wait for time and chance to deliver a new leader: a Boris Johnson or an Esther Mcvey or a Dominic Raab or a Priti Patel or a Tom Tugendhat.  In other words, someone not implicated in and tarnished by this long rout.

If that seems too stark a conclusion, they might want to ponder these questions.  If May backs off No Deal once, why wouldn’t she do so again?  Once one extension is sought, why not a second later?  Is her commitment to oppose a second referendum solid?