Britain’s ambassador to the European Union Sir Ivan Rogers dealt a blow to the UK’s Brexit negotiations by resigning. In a letter explaining his decision he is urging his fellow British civil servants in Brussels to assert their independence by challenging “ill-founded arguments and muddled thinking”.

He goes on saying that he was leaving now to give time for his successor to take charge of the lengthy negotiations process which starts in March.

However, he did not hide his disappointment by politicians who rejected his warnings about the upcoming problems in the Brexit process ahead.

He undelined that the structure of the UK Brexit negotiating team had not yet been resolved and that there is still no negotiating strategy yet.

“I hope you will continue to challenge ill-founded arguments and muddled thinking and that you will never be afraid to speak the truth to those in power. I hope that you will support each other in those difficult moments where you have to deliver messages that are disagreeable to those who need to hear them” he writes.

Rogers argument that it may take as long as 10 years for the UK to fully break from the EU has been a source of bitterness for Tory sceptics against him.