Jean-Claude Juncker claimed Theresa May “begged” him for help during a private Brexit dinner in which she appeared “tormented” with “rings under her eyes”, according to reports in the German press.
The European Commission president’s office has been accused of leaking the unflattering account of the meal, which saw Mrs May described as “despondent”.
In the highly personal account of last Monday’s dinner, Mrs May was said to seemed”anxious”, “tormented” and “discouraged”, according to German newspaper Frankfurter Allgemeine Zeitung (FAZ).
Mr Juncker was said to have described the Prime Minister to colleagues as looking like someone who does not sleep, and as a woman who once laughed but now has to work to avoid losing her temper.
After the dinner, a joint statement was released agreeing to accelerate Brexit talks.
Mrs May’s former chief of staff accused his former opposite number in Mr Juncker’s office of leaking the details of the Brussels dinner last week.
Nick Timothy blames Martin Selmayr, Mr Juncker’s chief of staff, for the account of the private meeting published by FAZ.
Conservative MP Jacob Rees-Mogg, said the unfavourable description of Mrs May was a negotiating tactic.
“I think it’s what you would expect in a tricky negotiation, that one side would try to undermine the confidence of the other side,” he said.
“We could all think of rude names to call Jean Claude Juncker but he should not be personal – it will sour the whole tone. It is much better to carry out in a spirit of cooperation.”
Earlier this year, Mr Selmayr was accused of leaking to FAZ details of a private dinner between Mrs May and Mr Juncker at 10 Downing Street, which the Commission president was said to have left “10 times more sceptical” than when he arrived.
The leaked report said Mr Juncker accused Mrs May of being “delusional”.
Mr Juncker later admitted the leak of the Downing Street dinner was a “serious mistake”.
Last week at the European Council summit, EU leaders said they would begin scoping work on future trade talks while making clear to Mrs May she must make more concessions on Britain’s divorce payment for negotiations to progress.
Mr Timothy, who worked for Mrs May at the time of the previous leak, said the new disclosure showed there are figures in Brussels who want Britain to leave the EU with either no deal or on terms which would punish the country for Brexit.
He tweeted: “After constructive Council meeting, Selmayr does this. Reminder that some in Brussels want no deal or a punitive one.”