There is an argument, which the prime minister may not see yet, that the 15% of her MPs who triggered a no-confidence vote in her may be doing her a favour.

Because having pulled that House of Commons vote on her Brexit plan, which was supposed to have happened last night, the damage to her authority was such that something had to give.

And of the three options of what would give - a general election, formal abandonment of her plan, or an attempt to get rid of her - the one that is least likely to end her time as PM is probably what is happening, the no-confidence ballot.

Theresa May speaks outside Number 10 on Wednesday morning. Credit: PA

What is more, having today explicitly framed the poll of her MPs as a referendum of her parliamentary party on her Brexit plan, she and that widely hated plan to quit the EU could arise reborn from the ashes.

"My Brexit is the only Brexit in town" she said outside Downing Street this morning. "Get rid of me and you get rid of that - and possibly any Brexit at all".

Her opponents on the Brexiter wing of her party say they welcome the fight on that battleground.

In fact they triggered the vote in the first place precisely because they hate her Brexit, and believe they have a better one.

The problem for them is they are very likely to lose. And at that point it probably won’t matter if even 100 Tory MPs will have shown themselves to have been against her, because more than 200 of her MPs will have backed her to remain in office for at least another year.

And a powerful majority of her MPs will have backed her version of Brexit.

In those circumstances a Brexit plan that looked totally doomed could yet be revived - because even her Tory critics would be under intense pressure, from Tory members, to rally round her.

This is Tory MPs' one chance of new leadership and either a different Brexit or no Brexit at all. And there is little in their conduct over the past year to suggest they have the stomach or backbone for those risks.

Candidates for Theresa May's job could include Jacob Rees-Mogg, Amber Rudd, Boris Johnson and Sajid Javid. Credit: PA

The chances of her actually losing, based on my sounding this morning, are slim.

But maybe 120 to 130 MPs will vote to get rid of her - and were that to happen, she would be severely weakened, and could yet decide to resign, even though she would not have lost in a formal sense.

If the vote against her was 100 or less, arguably she would emerge stronger than she is perceived to be right now.

So as I say, Jacob Rees-Mogg, David Davis, Boris Johnson, Steve Baker and Dominic Raab may in practice be doing her a good turn, against their dearest hopes and convictions.