The European Union has warned that it is "more likely than not" that Brexit talks will fail after Jean Claude Juncker accused Theresa May of being "deluded" in the wake of a tense Downing Street dinner.
The President of the European Commission launched a scathing attack on Mrs May after the meeting on Wednesday last week, the German newspaper Frankfurter Allgemeine Sonntagszeitung reported.
He reportedly claimed during the meeting that Brexit "cannot be a success" and threatened to end talks without a trade deal if Britain refuses to pay a "divorce" bill.
The Prime Minister said that the UK is not legally obliged to pay the EU anything as it leaves the EU. Mr Juncker and his colleagues responded by saying that Britain cannot simply cancel its membership of the EU as if it was a "golf club".
Today's FAZ report on May's disastrous dinner with Juncker - briefed by senior Commission sources - is absolutely damning.— Jeremy Cliffe (@JeremyCliffe) April 30, 2017
EU officials accused Mrs May of viewing Brexit through "rose-tinted glasses" after she said "let us make Brexit a success". Mr Juncker insisted: "This cannot be a success."
The pair also clashed over EU migrants as Mrs May pushed for an early deal during negotiations. The European Union's representatives said they were "astonished" by Mrs May's push for it to be sorted "by the end of June".
Mr Juncker suggested that this timetable was "too optimistic", pulling out of his bag "two piles of paper" - Croatia's EU entry deal and Canada's free trade deal - to highlight how complex talks are likely to become.
The most tense talks came over Britain's Brexit divorce bill. The European Union is calling on the EU to pay up to £50billion to fulfill its obligations to the EU.
Mrs May reportedly insisted that the UK is not legally obliged to pay the EU anything, which appears to have prompted an angry response. Mr Juncker suggested that without paying a divorce bill Britain would be unable to secure a future trade deal.
Anyone who doubts we are being led over a cliff I suggest you read the @JeremyCliffe 30-tweet account of the FAZ report on May/EU dinner— Alastair Campbell (@campbellclaret) May 1, 2017
After the meal Mr Juncker called Angela Merkel, the German Chancellor, saying that Mrs May was "living in another galaxy" and "deluding herself".
His call led to Mrs Merkel publicly warning that Britain was suffering from "illusions" about Brexit. Mrs May subsequently highlighted her comments and said that EU nations were "lining up" to oppose Britain and that talks would be "tough".
The European Union also appeared to reject calls by Mrs May for talks to remain confidential. The Prime Minister called for negotiations to be held in monthly, four-day blocks which would remain confidential until the end of the process.
The European Commission said that this would be "impossible" given the need to consult member states and the European Parliament over discussions. "All documents must be published," the report suggested.
Critics have rounded on Theresa May after the report made waves across the country.
Lib Dem leader Tim Farron said: "These reports blow a massive hole in the Conservative Party's arguments.
"Theresa May chose a divisive hard Brexit, with Labour's help, and now has no idea what to do next.
"This government has no plan and no clue and this shows it starkly.”
Shadow Brexit minister Keir Starmer told the Financial Times: “This is...evidence that May’s rigid and complacent approach to Brexit negotiations risks leading Britain over a cliff edge."
Number 10 rejected the claims, saying they didn't recognise the account. A spokesperson commented: "As the Prime Minister and Jean-Claude Juncker made clear, this was a constructive meeting ahead of the negotiations formally getting underway".