The ongoing deadlock with the EU has led many to expect the Article 50 exit talks will have to be extended beyond the March 29 deadline.

But local government bosses and Cabinet ministers have warned No10 as well as the Tory party’s chairman that its vote at the council polls on May 2 will be decimated if they are seen to have broken the key Brexit promise.

That gives the PM just a five week extra window to wrap up Brexit and pass all necessary new laws, and 12 weeks in total from now.