A quick thought on the famous Tory letters. If you want to spill the Tory leader, you need a set percentage of the Tory MPs to write to the 1922 Committee chairman. The current trigger level is 48, and the current chairman is Graham Brady MP. There is a lot of mystery about the process, because the chairman keeps the letters secret unless and until the trigger level is reached. It is not known, for example, if the letters expire after a set period and if so, what the period is.

But we can try to estimate this. I think we can rule out letters being held over from one Tory leader to the next – David Cameron, after all, resigned, so anyone who wrote demanding his resignation got what they wanted – so we know that the count was zero in June 2016. This implies that Brady spent part of the weird solstice weekend of that year burning or shredding highly confidential letters, which is in any case how I imagine the 1922 Committee chairman spends his time.

We know of precisely one letter – Andrew Bridgen MP says he sent one. He also claims to know of two others but he may be lying, misinformed, or deluding himself. I have seen an anonymous estimate of 44. And we know Theresa May is still prime minister, so the estimate is bounded by the trigger level, for a set of estimates (1, 3, 44, 47).

The Malatesta estimator suggests we should deal with potentially exaggerated estimates as follows: take the mean and subtract one-third. Rounding to whole parliamentarians, the mean is 24, and therefore the point estimate is 16. About a month ago, the PR company Edelmans provided what I think is the only precise roll-call of the Tories that’s available. They counted 37 Tories who might actually vote against the government, but classified 18 of them as “potentially persuadeable”. 37 less 18 equals 19, which really isn’t far off that number!

Head on the block: I therefore think the Tory Brexit rebellion will underperform its promises. Tellingly, none of them have resigned.

There are now reports that some MPs have sent letters saying “I have no confidence in Theresa May as leader but you can’t use this letter to support a leadership challenge without asking me first” which is… well, not surprising really.

Head on the block: I therefore think the Tory Brexit rebellion will underperform its promises. Tellingly, none of them have resigned.um.

This was written after the Cabinet meeting when they weaked-out and didn’t. I would also contend that repeatedly announcing you have the votes to no-confidence the prime minister and coming up short by 50% is pretty much the definition of underperforming on your promises.

repeatedly announcing you have the votes to no-confidence the prime minister and coming up short by 50% is pretty much the definition of underperforming on your promises.Um.

Tragically, Theresa May has acted over the last two years as if the Brexit Ultras were a significant parliamentary force. She has negotiated a Brexit deal that tried to please the Brexit Ultras, but has failed to do so and which is opposed by other significant sections of parliamentary opinion for the exact opposite reasons. She is left defending something that is a mess.