Theresa May’s hopes of securing a deal with Labour on Brexit before a crucial EU summit were fading on Thursday, after a second day of cross-party talks broke up without agreement and opposition to the initiative hardened.
Downing Street said negotiations with Labour would continue on Friday and that both sides were “mindful of the need to make progress” ahead of the European Council meeting next Wednesday, where the prime minister is expected to ask for a delay to Brexit beyond the scheduled date of April 12.
But while the initial talks between Mrs May and Labour leader Jeremy Corbyn on Wednesday were described as “constructive”, there was less optimism on Thursday as the two teams struggled to find common ground on a Brexit Plan B.
The apparent lack of progress was reinforced when attorney-general Geoffrey Cox told the BBC that if the talks failed the prime minister would be forced by EU leaders to accept a “long” delay to Brexit. “I mean longer than just a few weeks or months,” he said.
Mrs May announced talks with Mr Corbyn on Tuesday after she admitted her Brexit deal was deadlocked in parliament. Downing Street said she was approaching the talks in a “constructive spirit” and took care not to close down any plan B options.
But the prime minister’s move has been fiercely criticised by Tory MPs, with threats of a full-scale revolt if she accepts Labour’s proposal for a customs union between the UK and the EU after Brexit.
Many Labour MPs believe Mr Corbyn should play no part in helping Mrs May to deliver Brexit, and the party is split on whether it should demand a second “confirmatory” referendum on any exit deal.
“The government and the opposition hope to meet again tomorrow for further work to find a way forward to deliver on the referendum,” Downing Street said in a statement after senior Conservative and Labour figures held talks lasting more than four hours on Thursday.
But one shadow cabinet member said the government had not proved it was “prepared to flex over any lines we have called for”.
Much focus is on whether Mrs May and Mr Corbyn can agree to a customs union as the basis of a future relationship between the UK and the EU.
It is strongly opposed by Eurosceptic Tories, but Downing Street suggested it might be acceptable on the grounds that future parliaments “in generations to come” might decide to pull out of the customs union.
Cabinet ministers are deeply divided on how to break the Brexit impasse at Westminster. Chancellor Philip Hammond said on Wednesday that a second referendum was a “perfectly credible proposition”, but health secretary Matt Hancock said on Thursday he was “very, very strongly against”.
Another cabinet minister said there was no way Mr Corbyn would help Mrs May out of her Brexit crisis “It shows a fundamental misunderstanding of Labour politics,” he added. “There’s a complete lack of strategy.”
The shadow cabinet is also divided. Brexit spokesman Keir Starmer, backed by shadow foreign secretary Emily Thornberry, wants a second referendum on any exit deal but others are opposed.
Some 25 Labour MPs — including former minister Caroline Flint and others representing Leave-voting seats — wrote to Mr Corbyn on Thursday, saying another referendum should not be part of a deal.
If the talks between Mrs May and Mr Corbyn fail to produce an agreed Plan B, she has promised to test parliamentary opinion for different forms of Brexit — including her deal — in a series of Commons votes, but time is now short before Wednesday’s EU summit.
The earliest the votes could take place would be Tuesday. Such a step would be highly risky, not least because if Mrs May held indicative votes and no Brexit option received a Commons majority, she would arrive in Brussels with no agreed plan.
Since the EU is demanding to know from Mrs May what she would do with any extension to the Article 50 divorce process, Downing Street hinted that she would hold in reserve the idea of asking for a new Commons process.
“The European Council is likely to be looking for clarity on steps going forward in the UK parliament,” said Mrs May’s spokesman.
Ahead of the EU summit, Mrs May will have to formally request an extension to Article 50 in a letter to European Council president Donald Tusk, with Eurosceptics cabinet ministers opposed to a long delay to Brexit.
The prime minister will stress that Britain must be able to terminate the extension when — or if — her withdrawal agreement is ratified.
Senior EU diplomats are concerned that Mrs May will avoid explicitly requesting a long Article 50 extension to avoid upsetting Brexiters.
But London has been warned by Brussels not to expect EU leaders to impose a long extension without Mrs May asking for one.
One EU diplomat said he could see why Mrs May would “want Europe to set the date”. “That is very dangerous and will not work,” added the diplomat. “It is not possible.”