What did we learn about ministers’ relations with the civil service from top mandarin Sir Mark Sedwill?

Following the Priti Patel row, Britain’s most senior civil servant faced questions yesterday from MPs, writes John Rentoul

Boris Johnson shakes hands with Sir Mark Sedwill (PA)

Sir Mark Sedwill, who as well as being cabinet secretary is head of the home civil service, gave evidence to a select committee of MPs yesterday. It was a classically smooth and uninformative performance.

Naturally he was asked about the falling out between Priti Patel, the home secretary, and Sir Philip Rutnam, her former top civil servant. “There is a limit to what I can say,” said Sir Mark. Sir Philip has threatened to sue the government for constructive dismissal, but he has not started proceedings yet, Sir Mark told the committee.

It is unprecedented for a permanent secretary to resign in this way, saying he had been forced out by his minister and accusing her of lying, but Sir Mark was unflapped. He confirmed that he was indeed the “line manager” for all permanent secretaries, and that he had been torn, therefore, between his responsibility for Sir Philip and his loyalty to the prime minister, at whose right hand he sits in cabinet meetings.