The UK has been urged to table fresh proposals by Friday to break the Brexit deadlock.
Officials from the EU said they would work non-stop over the weekend if “acceptable” ideas were received within the next 48 hours to break the deadlock over the Irish backstop.
Theresa May’s efforts to resolve the Brexit deadlock have ran into difficulties in Brussels this week while the House of Lords inflicted a defeat over a key part of her strategy.
Diplomats said talks in Brussels on Tuesday led by May’s chief lawyer, Geoffrey Cox, failed to find common ground, with barely over three weeks to go before Britain’s scheduled departure on March 29.
“Things are not looking good,” one diplomat told Reuters after EU negotiators briefed envoys on the previous evening’s talks with Cox. Another described the mood as “downbeat,” although Brussels insiders were divided on whether May might yet accept an EU offer by next week — or risk an 11th-hour crisis at a summit on March 22.
Meanwhile, Jeremy Corbyn, who on Wednesday held talks with senior Tories to discuss possible alternatives to the PM’s deal, said he is “more certain than ever” MPs will back a deal to keep the UK closely tied to the European Union.
The Labour leader said he believed the commons would force the government to back a “sensible” Brexit plan.
Writing in the Daily Mirror, Corbyn said Labour would support a second referendum to prevent a “damaging Tory Brexit or a no deal outcome”, but stressed his efforts to find a deal.
On Wednesday he sat down with former Tory ministers Nick Boles and Sir Oliver Letwin, along with Labour’s Stephen Kinnock and Lucy Powell, to discuss their “Common Market 2.0” plan which would keep the UK in the single market and customs union.
May has already rejected the idea, however, insisting that single market membership would mean signing up to Brussels’ rules with no influence and accepting continued free movement of people.
She also rejects a customs union because it would restrict the UK’s freedom to strike trade deals around the world after Brexit – a key prize for those who championed leaving the EU.
On Wednesday night the House of Lords gave May a potential new headache when they passed an amendment calling for the government to negotiate a customs union with the EU.
Supporters of the amendment to the Trade Bill argued MPs should have the opportunity to “think again” on the issue of a customs union.
The government pointed out MPs had already rejected such a proposal, with Tory frontbencher Lord Bates telling peers: “It doesn’t need a chance to think again.”
But writing in the Mirror, Corbyn suggested MPs were coming round to the idea of a soft Brexit.
He said he was “more certain than ever that we can find a way to work across Parliament to force the government to back a sensible Brexit plan that protects jobs”.
Corbyn added: “I will continue to reach out to get a decent Brexit deal so our country can spend more time talking about our children’s future than a customs union.
“Labour respects the result of the referendum and a close economic relationship is the best Brexit compromise for both 17 million Leave voters and 16 million Remain voters.
“But we can’t accept a damaging Tory Brexit or a no deal outcome, so we also support preparing for a public vote in case Parliament is not able to achieve a sensible Brexit.
“We will do whatever we can to find a solution that can unite the country so, together, we can face down the real challenges and seize the opportunities in this moment of great change.”
Both the UK and EU sides admitted talks in Brussels on efforts to find a way to resolve the difficulties over the Northern Ireland backstop had been “difficult”.
The European Commission said there was still “no solution” to the impasse over the Irish backstop following a meeting between the EU’s chief negotiator Michel Barnier and Attorney General Geoffrey Cox and Brexit Secretary Stephen Barclay.
The meeting took place as May prepared for next week’s crunch “meaningful vote” in the Commons on her Brexit Withdrawal Agreement, which Downing Street has insisted will go ahead on Tuesday as planned despite the negotiations with Brussels stumbling,
It is becoming increasingly likely No 10 will not secure significant EU concessions on the backstop and May is expected to try to sell her plan to MPs and the public later in the week, potentially with a speech.