It’s become a well-sourced article of faith that the problem that Conservative Brexiteers have is that they have the numbers to trigger a vote of no confidence in Theresa May’s leadership of the Tory party (they need 15 per cent of the parliamentary party to sign a letter calling for one, that is to say, 48 names) but not enough to win one (for which you need 50.1 per cent of the parliamentary party, i.e. 156 MPs).

It’s true to say that, if you were to pick up the phone to every member of the parliamentary Conservative party, you would struggle to get close to 156 people to commit to voting against May even privately. In fact there is a lot of hostility to the idea of triggering one early because under Tory party rules, if the leader survives a confidence vote you can’t have another go for a year. (That’s one reason why, as Patrick explained in greater detail to readers of our subscriber only Sunday briefing this morning, Johnny Mercer’s outspoken comments about the party leadership are losing him friends among his fellow Conservative MPs.)

But that wouldn’t give me any comfort in Downing Street. The settled will of the majority of the Conservative parliamentary party is that Theresa May needs to go shortly after the United Kingdom formally leaves the European Union in March 2019 and the prospect of extending her political shelf life deep into the winter of 2019, which any failed confidence vote would do, is an anathema to them.

The fear is particularly acute if you are on the foothills of government or even in the Cabinet. A May who survived a confidence vote, even narrowly, would be immediately strengthened (Katy Balls lays out the consequences of that well over at the i) perhaps even to the point that she could carry out a significant Cabinet reshuffle: bad news for any of the politicians currently near the front of the pack as far as the next leadership race goes.

If enough MPs do decide to send their letters of no confidence in, May could survive: but the overwhelming likelihood is that Conservative MPs would decide that getting rid of May earlier than they’d like is better than the risk of not getting rid of her at all.