Britain's Labour opposition on Friday pulled the plug on six weeks of talks on a Brexit compromise with Prime Minister Theresa May, blaming the "weakness and instability" of her government.
The discussions "have now gone as far as they can," Labour Party leader Jeremy Corbyn said in a letter to May, pointing to "important policy gaps" between the two sides.
"The increasing weakness and instability of your government means there cannot be confidence in securing whatever might be agreed between us," Corbyn said.
The main opposition leader said he would therefore continue to oppose the government's deal in parliament, although he would "carefully consider any proposals the government wishes to bring forward to break the Brexit deadlock".
The announcement came after May on Thursday agreed to set out early next month a timetable for her departure.
A poll put the Conservatives in fifth place for the European Parliament elections
MPs three times rejected the divorce deal May struck with Brussels, further weakening her authority and forcing her to reach out to Labour.
MPs are due to vote for a fourth time in early June on the terms of Britain's withdrawal from the EU.
Labour, which favours much closer economic ties with the European Union after Brexit, were concerned May could be on her way out and that her successor might not stick to any bargain she struck.
Meeting with party bigwigs
On Thursday, May held a meeting with the 1922 Committee of backbench Conservative MPs fleshing out plans for her departure.
Graham Brady, who chairs the 1922 Committee, said May would do this after a parliamentary vote in the week beginning June 3 on legislation to approve her EU divorce deal.
"We have agreed that she and I will meet following the second reading of the bill to agree a timetable for the election of a new leader," Brady said, whatever the outcome of the vote.
It is thought that May will trigger a leadership contest once the Withdrawal Agreement Bill either falls, as seems likely, or reaches completion.
The timetable is likely to mean a new Conservative leader, and therefore prime minister, should be in place before the party's annual conference in September.
Britain's EU exit date has been twice pushed back, from March 29 to October 31.
The pound sank on renewed concerns Britain will leave the EU with no deal.
Investors sold sterling on worries that May's likely defeat could lead to a hardline Brexiteer taking her post and pushing for a hard EU exit, which most commentators warn would hammer the economy.
"The chances of a feasible Brexit solution being achieved seem to be falling by the day," said OANDA senior market analyst Jeffrey Halley.
The internal Conservative pressure on May increased after the centre-right party suffered heavy losses in English local elections on May 2.
A poll in The Times newspaper on Friday put the Conservatives in fifth place for the European Parliament elections, to be held in Britain on Thursday.
The Brexit Party were on 35 per cent, the Liberal Democrats 16 per cent, Labour 15 per cent, the Greens 10 per cent, the Conservatives 9.0 per cent, Change UK 5.0 per cent and UKIP 3.0 per cent.
YouGov interviewed 7,192 British adults between Sunday and Thursday.
Former foreign secretary Boris Johnson is the bookmakers' favourite to replace May. He revealed Thursday that he would run.