Brexiter Tory MPs are demanding that Theresa May makes next month’s customs union vote a confidence vote, and are making clear that letters will go in to Graham Brady if she attempts to further fudge the issue.

It is now the view of Leavers that the customs union has to be made an issue of confidence (though it can’t be a formal vote due to the Fixed Term Parliaments Act) and this has to happen next month. The government’s fudge so far has led the EU to reject the UK’s proposals and offer a binary choice between a customs union and no deal. May has to say once and for all that Brexit, and her premiership, means not staying in a customs union. This has to happen next month – if the crunch is delayed further the negotiation on customs will be doomed as Brussels and Remainers continue to work to undermine the UK position, and it will be too late to turn it around. Brexiter MPs know they cannot allow a situation where May is outplayed in the negotiation with Brussels, defeated by Remainers in the Commons and bounced into ‘reluctantly’ accepting membership of a customs union. 

Following yesterday’s Sunday Times story, Brexiter ministers let it be known that they could not stay in the government if May caved on the customs union. There was talk that David Davis would resign if Number 10 capitulates (though this would not be the first time he has threatened to quit). After Sajid Javid’s tweet yesterday it’s clear that it’s not just Brexiters for whom this is a red line. Certainly a raft of junior ministers would go. In the end Number 10’s Cabinet wargaming is a moot point. They know that if they surrender on the customs union, the letters would immediately go in and that would be that…