It was less than 20 minutes before facing the cameras in Salzburg that Theresa May discovered the scale of the EU ambush about to befall her.

Huddled in front of an aide’s iPad propped up on a table in the British delegation room, she watched as Donald Tusk read from a prepared script pronouncing the death of her Chequers blueprint in nine words. “The suggested framework for economic co-operation will not work,” he said bluntly.

No one in the room had any inkling it was coming, certainly not the prime minister who had talked with Mr Tusk 30 minutes before. Not Oliver Robbins, her chief Brexit negotiator, who was sitting next to her and who had had responsibility for masterminding the summit strategy. Nor Sir…