Ten days ago, Theresa May finally lost her patience. Backbench MPs had been invited into the chief whip’s office in No9 Downing Street for a presentation on Brexit by Gavin Barwell, the PM’s chief of staff. Still just a backbencher, Jacob Rees-Mogg was among them.

When the time came for questions, he took his chance, suggesting that Britain push for no deal and simply keep the border with Ireland open, daring Brussels to close it. It is the sort of “It’s quite simple, really” suggestion that a certain type of Brexiteer specialises in.

May was having none of it. She snapped back that resorting to WTO trade rules would harm the economy, warned of the security risk at the border and suggested that it could