The mood among pro-Brexit Conservative was summed up by Simon Clark, who told the prime minister directly that she had as "failed to reassure" MPs that the United Kingdom will definitely leave the customs union by December 2020, amid fears that the United Kingdom could be wedded to the EU's customs arrangements for years and years to come.
President Macron is seen as a key figure in the negotiations whose outspoken criticism of Britain's Brexit vote led to the Prime Minister's proposals being rebuffed at an earlier summit in Salzburg last month.
No 10 said nobody at the meeting had threatened to resign, leaving May free to ask European Union leaders on Wednesday night for their help in kickstarting the stalled negotiations.
Loiseau said "everything is on the table" and France had set up the mechanisms to pass emergency legislation to deal with the chaos expected in the event of "no deal".
In Dublin, Irish Prime Minister Leo Varadkar said on Tuesday he still believed a positive outcome was possible, but added: "I am disappointed and concerned.it has not been possible to make the decisive progress we so urgently need".
"I'm convinced that if we as a Government stand together and stand firm, we can achieve this", she said.
Clearly not in a place where we wanted to be on Brexit at the moment.
Talks stalled over the weekend between UK Brexit secretary Dominic Raab and European Union chief Brexit negotiator Michel Barnier, and that is what led to the standstill we're seeing now between the two parties.
"We should nevertheless remain hopeful and determined, as there is good will to continue these talks on both sides". The so-called backstop is created to prevent a hard border on the island of Ireland after Brexit.
Multiple reports suggest Cabinet resignations have been put on hold for at least another day with restless ministers prepared to give Prime Minister May more time to satisfy their demands.
"We are not there yet", he said. For a breakthrough we need new facts.
"For now, Britain is negotiating with Britain", Belgian Foreign Minister Didier Reynders said, referring to May's troubles with her own cabinet and supporters.
A breakthrough on how to keep the border between Ireland and Northern Ireland as porous as possible appeared close enough on Monday that European Union officials thought tomorrow's summit would be a celebration of the elusive Brexit deal.
Also attending were International Development Secretary Penny Mordaunt, Transport Secretary Chris Grayling, Treasury Secretary Liz Truss and Attorney General Geoffrey Cox.
If the existing transition expired before it was ready, then the original Northern Ireland-specific backstop would have to kick in.
In case a Brexit agreement is not reached - "or in case it is rejected" - leaders at Wednesday's meeting "will discuss how to step up our preparations for a no-deal scenario", Tusk said....