The top diplomat of the U.K resigned three months before the British Prime Minister triggers Article 50 of the TEU.

Sir Ivan Rogers did not give a reason for his shock resignation but was known to be a “pessimist” about the prospects of a post-Brexit U.K.

Rogers worked with Tony Blair and was appointed by David Cameron Britain’s Ambassador to the EU in 2013. His four-year term was expected to finish in November 2017.

The resignation was hinted by the the Financial Times on Tuesday but was not considered imminent. The BBC reports that his resignation suggests a failure to cooperation with Prime Minister Theresa May.

In December, the British diplomat came under fire for suggesting the Brexit deal could take a decade to conclude. Brexit campaigners were enraged that the former secretary of the most prominent Conservative Europhile, Ken Clarke, could remain in place.

Nick MacPherson, who served as Whitehall’s head of the Treasury (2005-2016) tweeted that the government was embarking on a “destruction” of EU expertise.

Former European Commissioner and negotiator for the City of London, Sir Peter Mandelson, said Roger’s resignation mean diplomats were inhibited about offering blunt advice. “Our negotiation as a whole will go nowhere if ministers are going to delude themselves about the immense difficulty and challenges Britain faces in implementing the referendum decision,” Mandelson said.

But, the Leave campaign and UKIP donor Arron Banks hailed the resignation of a member of the “establishment’s pro-EU old guard.” UKIP spokesman Gerard Batten officially welcomed Rogers’ resignation. The former leader Nigel Farage expressed the wish that other diplomats should follow.

(New Europe)