British Prime Minister Theresa May met European Commission chief Jean-Claude Juncker over dinner in Brussels on Monday in a bid to unblock Brexit talks ahead of a decisive EU summit this week.
May spoke by telephone with the German, French and Irish leaders ahead of the meeting as fears grow that negotiations on Britain's exit from the bloc could end without a deal.
May and Juncker will be joined at the dinner table by British Brexit minister David Davis and his EU counterpart, chief Brexit negotiator Michel Barnier, as well as the top aides to the two leaders.
Juncker declined to answer questions about the content of the meeting ahead of time, telling reporters in Brussels: "I will meet Mrs May this evening, we will talk and you will see the autopsy."
EU leaders meeting in Brussels on Thursday and Friday are due to decide whether or not negotiators can move on to discussing post-Brexit trade ties with Britain if "sufficient progress" has been made in divorce talks.
The indication from the EU side is that they will postpone their decision to a summit in December as the break-up negotiations are currently deadlocked, particularly over the multi-billion-euro exit bill the EU says Britain must pay.
The EU has also demanded progress on the rights of three million European citizens in Britain, and on the future of Northern Ireland.
But Britain is still hoping for a positive signal that will ease growing concern, particularly on a two-year transition period to ease the "cliff edge" for businesses and citizens of a sudden departure.
The 27 other EU leaders are set to agree at the summit that they will launch internal preparatory work now on the transition and future trade deal so they can move to the next phase quickly in December, a draft summit statement said.
"We are relatively close when it comes to the transition," a European source said on condition of anonymity.
But they toughened their conditions in the latest version of the draft under pressure from France and Germany, who want the bill to be settled before any movement on trade.
With criticism of her Brexit strategy building up at home from both moderates and hardliners within her own Conservative party, May is hoping for a breakthrough that will bolster her position and ease some of the uncertainty around Britain's withdrawal.
"We've always said we want Britain leaving the EU to be a smooth process and this is part of achieving that," May's spokesman said of the 90-minute dinner.
The trip, announced at the last minute, takes place as economic storm clouds gather for Britain, with companies warning they will have start shifting some operations to the EU by the end of the year unless there is more certainty on Brexit.
May spoke to German Chancellor Angela Merkel on Sunday and the two agreed "on the importance of continued constructive progress in the UK's exit negotiations", according to a statement from her Downing Street office.
She is also due to speak to French President Emmanuel Macron while she also telephoned Irish Prime Minister Leo Varadkar.
British Foreign Secretary Boris Johnson also sought to drum up some goodwill on Sunday by hosting a group of East European foreign ministers for talks on security and light-hearted country walks at his official residence in Kent, southeast England.
"Let's put a tiger in the tank, let's get these conversations going and stop letting the grass grow under our feet," Johnson said as he arrived for a meeting with his EU counterparts in Luxembourg on Monday.
Luxembourg foreign minister Jean Asselborn however said they would have to wait until the end of the year.
"Father Christmas comes in December and there is also a summit then. So we have a bit of time to take stock and reflect on how to move the plough in the right direction," he said.
Ahead of May's meeting with Juncker, commentators pointed to the bad taste left by their last encounter in April.
Details were leaked to German newspaper Frankfurter Allgemeine Zeitung in which Juncker reportedly said May was in a "different galaxy", while May accused the EU of trying to influence British elections.