In the last few weeks we have witnessed a prince of the civil service, the prime minister’s chief adviser on Brexit, Olly Robbins, changing crucial government policy, with embarrassing and damaging consequences. This is a man who has been allowed to usurp David Davis, the elected secretary of state, as chief Brexit negotiator.

Robbins is a shadowy figure in the corridors of power. A real, live, modern-day Sir Humphrey — and someone who certainly subscribes to the ancient but false dictum that “the man in Whitehall knows best”.

Robbins is understood to have persuaded the PM to embrace the shape of the Florence speech last autumn, which gave ground to Brussels without asking for anything in return. In December, he then persuaded Theresa May to