British Prime Minister Theresa May returned to face EU leaders Friday after they rebuffed her pleas for help to sell her Brexit plan back home and warned of the growing threat of a "no deal."
May had sought to persuade her 27 colleagues she could overcome huge opposition to the divorce deal among British MPs if they gave her some assurances over the thorny problem of the Irish border.
But they were not convinced, and European diplomats said May had been unable to explain what she wanted or how she could deliver a British parliamentary majority to endorse the deal.
"The signals we heard yesterday were not particularly reassuring on Britain's capacity to honour the commitments that were made," Belgian Prime Minister Charles Michael said.
"So we will make sure to prepare for all scenarios and prepare also for a no deal scenario," he added, as he arrived for the second and final day of the EU summit.
On Thursday, European Commission president Jean-Claude Juncker repeated statements made all week by European leaders that "there is no room whatsoever for renegotiation" of the deal.
May postponed a vote in the House of Commons this week on the Brexit deal to avoid a crushing defeat, but has promised it will take place next month, by January 21 at the latest.
This is uncomfortably close to Britain's scheduled exit day on March 29, 2019 - and Juncker said he was stepping up preparations in case it leaves with no deal in place.
Austrian Chancellor Sebastian Kurz added on Friday: "There is a withdrawal deal, and there is an urgent necessity to take decisions. We should avoid a no deal scenario."
May did not speak as she arrived for the summit, where she met with French President Emmanuel Macron before EU-wide discussions on migration, Russia and climate change.
She came to Brussels wounded by a confidence vote on Wednesday night, which she won but in which 117 MPs - more than one-third of her Conservative party - voted to oust her.
Opposition to the Brexit deal in Britain is focused on a so-called "backstop" arrangement designed to keep open the border with Ireland if and until a new UK-EU trade deal is signed.
May is seeking "legal and political assurances" that this will not keep Britain trapped indefinitely in an EU customs union.
Several EU leaders have talked of offering "clarifications" and "explanations", and a statement issued after they talked without May late Thursday emphasised they will try to ensure the backstop is never triggered.
But, while an early draft of the conclusions said the EU "stands ready to examine whether any further assurances can be provided" on the backstop, this was removed from the final version.
"Colleagues were so exasperated that she left with less than she could have got," a European source said.
May told EU leaders they must help her "change the perception that the backstop could be a trap from which the UK cannot escape", according to a British official.
"With the right assurances, this deal can be passed. Indeed it is the only deal that is capable of getting through my parliament," she told them.
But European sources said the room was tense, with German Chancellor Angela Merkel and other leaders repeatedly interrupting May to ask her what she wanted and how she could deliver it.
Another source who had been in the room told AFP on Friday that May had contradicted herself and failed to say how any assurances on the backstop might work, to the consternation of fellow leaders.
On Friday, however, Luxembourg Prime Minister Xavier Bettel on defended May, saying she "did a good job, she got the best possible deal" despite being able to deliver her own party's lawmakers.
"The problem is the MPs in London," he said.
"The fact is for internal political reasons in the UK some people try to gamble the relation between the EU and the UK for the future. And it's bad."
May has faced constant criticism to her Brexit strategy from hardline anti-Europeans in her party, while the Northern Irish party which props up her government also opposes her deal.
They want the backstop out of the agreement entirely -- but Irish Prime Minister Leo Varadkar once again emphasised the need to have legal guarantees on keeping open the Irish border.
"By resolving it in the withdrawal agreement we can make sure no side uses the threat of a border in Ireland as part of leverage in the future relationship talks," he said.