As is often the case, the Foreign Secretary on Monday evening summed up the PM’s worst nightmare, when tweeting that surely everyone can agree that Jacob Rees-Mogg is a principled MP who only “wants the best for our country”.
Note well that he didn’t say his fellow Brexit purist only wants the best for his party.
And there lies why May has struggled to even describe a detailed policy for the UK’s future relationship with the EU, let alone secure agreement for it.
The point is she fears - correctly - that when it comes to what Brexit represents, for a Mogg, a Cash, a Bone, there are versions of it regarded by the true Brexiters as so toxic to the national interest they would rather see this minority government fall than collaborate with it.
So in that sense it may well be largely irrelevant that the centre of gravity in Parliament since May’s ill-starred election of 2017 has been for a softer Brexit which would see a Brexited Britain opting-in to many of the EU’s institutional arrangements, with the intention of minimising possible shocks to our trade and security.
Because the point is that when it comes to the design of Brexit, May has learned over the past year that the soft-Brexiters - the Grieves and Morgans, the Clarkes and Hammonds - will in the end put their jobs and keeping their party in power above their EU convictions, whereas she can’t ever be certain when she looks in the gimlet eyes of the true Brexiters that they won’t bring the whole house crashing down.
So goodness only knows what will happen after the Cabinet meeting at Chequers on Friday, when May’s colleagues tell me there really will be no more fudge, that we’ll see a coherent British policy for our future customs and trading arrangements with the EU.
It is a wholly irrelevant for now whether the rest of the EU will wear and approve the likely Swiss-style hybrid of effectively staying in a single market and customs union for goods and agriculture and withdrawing to an extent for services (for better or worse, the bulk of our economy - AS YOU KNOW!).
This model of being, in Mogg’s formulation, a semi-vassal state is seen by its Downing Street designers as - conceivably - sufficiently inimical to Boris Johnson that he might just decide he’d rather free himself from the shackles of high office to say what he really thinks (as a columnist reborn, and - cripes - earning what he would think of as proper money again).
And that could conceivably trigger a guerrilla coup by the true Brexiters to topple May.
Or again it might not.
We’re all mugs when betting on what will happen in British politics in just the next hour, let alone the next few days.
The only certainty is uncertainty.