But Cameron, a friend and old Etonian classmate of the Prime Minister’s told the British press, once put off a call from Obama to finish a tennis match.

“I played tennis with him at Chequers one day,” Charlie Brooks told the Racing Post. “I won the first set easily, then he won the second set, and then someone came up to him and said ‘Er… Mr Obama is on the phone for you, Prime Minister.’ He said: ‘I think we’ve got time for a third set – tell Mr Obama I’ll ring him back.’ He obviously thought he had me on the ropes, and I beat him two sets to one.”