So the PM loses another historic Brexit vote - and by an embarrassing margin of 45.
Which is the problem.
Because the EU 27's government heads want and need reassurance that if they were to make humiliating concessions, such that the UK Attorney General were one day able to say there is a guaranteed route out of the so-called backstop for the UK, MPs might actually - at the very last - vote for a Brexit deal.
But if Theresa May can't even win a majority for a motion that simply notes that talks with the EU continue (sort of) - a motion that is really just a way of wishing her luck in the backstop talks - EU leaders will rightfully query how she should could possibly win when MPs are actually presented with a definitively changed backstop?
So this is how it will probably now play out.
On February 27, the PM may finally and preemptively - before any vote on the so-called Cooper/Letwin amendment - surrender to MPs' lobbying and agree to ask the EU for a Brexit delay.
Some of her close associates tell me that she could do this, although it would mean defying all precedent and deliberately facing down her ERG Brexiter MPs - who would go berserk.
The alternative would be for her to continue to maintain a formal position of opposing a delay to Brexit.
But if she continues to insist that a no-deal Brexit on March 29 is the default position, that would lead 15 or so ministers, including a minimum of three in the cabinet (Amber Rudd, David Gauke, Greg Clark) to resign - because they are so implacably opposed to a no-deal Brexit that they would insist on voting for the Cooper/Letwin amendment, whose effect would be to force her to pursue the EU for a Brexit delay.
Either way, by the end of February the PM will probably be in a position of knowing that any talks that are still going on to tweak her Brexit deal must be combined with a request for a Brexit delay.
At that point, my powers of foresight are exhausted.
The point is what happens next depends on whether backbench MPs do what the senior Tory Sir Oliver Letwin says they must do - which is to launch a coup d'etat, seize power from the executive and vote for the kind of Brexit (or no-Brexit via a referendum) they actually want.
As I have said, their ability to do that is untested and uncertain.
I will elaborate later, but there is no certainty - as I have been boring on about - that they can avert a no-deal Brexit.