PM to meet Juncker and Barnier as Merkel says a ‘very important offer’ has been made to Britain

Theresa May has made an 11th-hour dash to meet EU leaders in Strasbourg as the government insisted the meaningful vote on her Brexit deal would go ahead on Tuesday as planned.

May was greeted in Strasbourg by Jean-Claude Juncker and Michel Barnier as she arrived in pursuit of a Brexit compromise late on Monday, after a phone call with the European commission president earlier in the day.

Ambassadors for the 27 EU member states were told at a briefing that the negotiations had become more combative. One source at the table said if the UK was choosing the impossible, it was choosing no deal.

It was, however, disclosed that the prime minister had been ready to strike a deal on Sunday with Juncker but that she was overruled by her cabinet.

Diplomats were told that talks at the weekend had gone “up and down, up and then sadly down again”, according to one source, leading to plans for a visit by the prime minister on Monday morning to be ditched.

The EU has rejected proposals by the attorney general, Geoffrey Cox, that would construct something close to a unilateral exit mechanism from the Irish backstop but leaders were on Monday keen to talk up the offer they had made, and avoid another delay to the meaningful vote.

The German chancellor, Angela Merkel, said that Brussels made a “very important offer” during the weekend’s talks. “I think that a very important offer has been made to Britain and now it’s up to Britain to respond to these offers,” she told reporters in Berlin.

The deal proposed by Michel Barnier included a joint interpretative statement that would add legal force to previous assurances the EU would make maximum effort to find alternatives to the backstop.

The UK and the EU will also make unilateral statements about the temporary nature of the backstop, with the British government likely to lean on revised legal advice from Cox.

The commission’s secretary general, Martin Selmayr, warned the EU ambassadors, however, that the situation in London was fluid and that the chances of a general election had increased in recent days.

He said that the safest delay to Brexit would be up to 23 May, ensuring that elections to the European parliament would not create complications. He added, however, that the EU may have to offer the UK a long extension of article 50 should May’s government fall.

Barnier, in turn, was said to be indignant about Cox’s interview in the Daily Mail in which he said that he would find a way to allow the UK to unilaterally quit the backstop.

The attorney general’s claim that the UK could trigger an arbitration mechanism “on the very first day we entered” the backstop was read out to EU ambassadors by an incredulous Barnier.

May has a matter of hours to table a motion to parliament in time for a vote on Tuesday. Speaking in the Commons, the Labour leader, Jeremy Corbyn, said parliament would not tolerate further delay. “Time and time again this prime minister has failed to negotiate, refused to compromise, and delayed and delayed,” he said.

“After three months the prime minister has not achieved one single change to her deal; she is simply running down the clock.”

The junior Brexit minister Robin Walker, who was sent out to answer the urgent question from Corbyn, said the vote would not be withdrawn at the last minute and that the attorney general would publish revised legal advice before the vote.

The Commons Speaker, John Bercow, said May or another cabinet minister might give a planned statement on the current state of the negotiations as late as 10pm on Monday night.

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Walker said that talks with Brussels were at “a critical stage” and were continuing. “The attorney general’s legal analysis will be updated following the outcome of negotiations,” he said. “He will be publishing his legal analysis document on any document that is produced and negotiated with the EU before the house meets tomorrow.”

The independent MP Anna Soubry said any motion and any amendments MPs would wish to table had to be be put down before the House of Commons rose on Monday night, but Walker would only say that the motion would be published “as soon as it can be”.

Bercow said that the House of Commons’ rules required the motion to be published by 10.30pm on Monday night, although indicated he would allow so-called “manuscript amendments” that are allowed to be tabled by MPs in extreme circumstances on the day of a debate.

The prime minister had earlier come under pressure from Eurosceptics to pull the meaningful vote and pass a motion showing Brussels that parliament would approve a deal with a time limit on the backstop.

However, Nick Boles, one of the Conservative MPs leading efforts against no deal, said calling off the vote would not satisfy parliament. “I am sure that the prime minister will honour these three commitments. If she doesn’t she will forfeit the confidence of the House of Commons,” he said.

Asked whether she would resign, the prime minister’s spokesman said there was “nothing to suggest” that outcome, though government sources have suggested they believe May could offer her resignation to hard Brexiters in exchange for voting for her deal.

Labour’s Yvette Cooper has said she and Conservative MPs would attempt to force votes on an extension of Article 50 on Thursday should the prime minister pull the votes, saying it would be a “straight-up lie” to parliament if Theresa May changed her plans.