Ian Duncan Smith, Conservative MP, has claimed that the replacement for Sir Ivan Rogers must want Britain to leave the EU.  Two possible replacements have been discussed.   They are treasury official Tom Scholar, or Bank of England deputy governor, Sir John Cunliffe.

Former leader of UKIP and one of the leaders in the Brexit campaign, Nigel Farage said of Sir Ivan, “He knew very well what he was doing.

“Probably also knew very well what he was doing when that previous email got leaked.”

“When a civil servant starts to go public on stuff that you, as ministers, can no longer trust that individual.

“You must have absolute trust and cooperation and you cannot have this stuff coming out publicly.”

Mr Duncan Smith, in response to Sir Ivan’s claims that the government didn’t have a plan, said, “We are leaving the rule of European law. We are taking back control of our laws.

“There’s a problem here for the civil service. They have never faced a challenge like this before.

“They are having to tear up the rule book on what they normally do with regard to their relationships in the EU.

“They are now having to accept and understand that we are leaving.”

Whitehall staff were quick to rally round the departing ambassador with Sir Simon Fraser, former head of Foreign Office staff saying Sir Ivan was a “highly intelligent, knowledgeable and experienced official.

“I do think that his sort of in-depth knowledge and expertise is a loss as we go into what is going to be, as [Brexit secretary] David Davis himself has said, a very complex set of negotiations.”

Sir Ivan’s resignation has been described as a “blow” in some areas as the Prime Minister prepares to trigger Article 50, the formal process for leaving the EU.  Key people in the Remain camp such as Nick Clegg are concerned that a pro Brexit replacement will mean a harsher deal for Britain in the negotiations.