A lavish dinner in the opulent setting of the Felsenreitschul theatre in Salzburg on Wednesday failed to smooth the way.
"Europe isn't an a la carte menu", French President Emmanuel Macron said. "Those people are liars". Even in her private meeting with Mr Tusk, he had not given her any indication of the level of criticism he was about to make. It came after Mr Gove called on Eurosceptics to get behind Mrs May's Chequers plan by arguing it can always be adapted after Brexit.
"The suggested framework for economic cooperation will not work, not least because it risks undermining the single market".
But nothing official will come out of the two days in Salzburg, as it is an informal meeting.
"On the economic partnership, there is no solution that will resolve the Northern Ireland border which is not based on the frictionless movement of goods", she said.
But London says this would undermine the U.K.by treating Northern Ireland differently from the rest of the country.
May said she would "shortly" bring forward new proposals on the so-called backstop on how to carry out regulatory checks on goods going in and out of Northern Ireland. Tusk said a special Brexit summit could be held in mid-November if things progress as hoped - but only as a "punch line" if most of the deal had already been agreed.More news: Spider Webs Cover Entire Greek Lagoon
Macron did not say who he was targeting with his "liars" remark, but Britain's former foreign secretary Boris Johnson and former Brexit negotiator David Davis - who both campaigned strongly for Britain to leave the European Union - resigned in recent months during talks on the divorce deal. In practice, to allow for parliamentary ratification, that means a deal must be struck in the next couple of months.
He added: "The Irish question remains our priority too and for this we need only goodwill - which we feel, the atmosphere was better than two or three weeks ago - but the Irish question needs something more than good intentions".
The prime minister acknowledged that she had had a "frank bilateral" with Tusk an hour before her end-of-summit press conference in which she was forced to defend Chequers and maintain that it was possible to reach a Brexit deal in the autumn.
Scottish First Minister Nicola Sturgeon has reportedly written to United Kingdom opposition leaders calling for them to back an extension to Article 50 if no deal is reached and warned the PM against taking the country "off the Brexit cliff edge".
Some leaders expressed deep frustration.
- French President Emmanuel Macron said leaders of the Brexit campaign who told British voters it would be easy were "liars" and leaving the European Union was "not without costs".
Macron added that it was true that Brexit negotiations had been complex and lengthy, but said: "That fact must not be exploited by those very people who are the cause of this problem, who got us into the Brexit situation and who now tell us that Europe is going from crisis to crisis". David Davis, the former Brexit secretary, said in a speech yesterday that the European Union "will demand more concessions" beyond Chequers to get a deal. Both sides want to show a tough face.
Sir Mike Penning, a former defence minster who voted Leave before backing Mrs May for the party leadership in the aftermath of the referendum, told the Telegraph she had treated Tory MPs "like children who belong on the naughty step".
That's because Donald Tusk has been seen as one of those brokers in the Brexit talks who has been trying to make things work, and trying to urge others who are more reluctant to do so, to show the United Kingdom a little flexibility.