But senior colleagues fear any hint of a climbdown could be enough to trigger cabinet resignations – including that of Foreign Secretary Boris Johnson, plunging her administration into further crisis.
With representatives of all 28 member states gathering in Brussels for an EU summit, Mrs May was urged to shift her “red lines” on Brexit at next week’s meeting at Chequers – with the implication that any such move would be viewed favourably on the continent.
Speaking prior to the start of the summit, European Commission president Jean-Claude Juncker warned: “We cannot go on living with a split cabinet.
“They have to say what they want and we will respond to that.”
Mrs May will next week try to persuade ministers to adopt a white paper which would commit the UK to stay close to the EU’s customs union and single market in goods, reducing the risk of a “hard Brexit”.
But one minister told the Financial Times this could trigger a cabinet revolt, adding: “We could be looking for a new foreign secretary in two weeks’ time.”
Mr Johnson’s allies continue to insist that he has no intention of resigning and will instead be fighting to hold Mrs May to the Conservative Party election manifesto pledge to take Britain out of the single market and customs union, reports the FT.
Meanwhile, the EU27 – consisting of all of the members of the bloc other than the UK – will today adopt communiqué vowing to improve its offer to Britain if Mrs May softens her stance, including opposition to a role for the European Court of Justice in a future trade deal.
And leaders have urged her to speed up the process as March 29, 2019 – the day the UK officials leaves the EU – draws closer.
Mark Rutte, Dutch prime minister, said: “Time is getting shorter and shorter to get an agreement.
“We don’t have time.”
Leo Varadkar, Ireland’s prime minister, added: “We did expect that we would make more progress – or any progress really.”
He also cast doubt on Mrs May’s idea of a partnership between Britain and the EU based on “mutual recognition” of each other’s rules, saying: “Any relationship that exists in the future between the EU and the UK isn’t going to be one of absolute equals.
“We’re 500m people, the UK is 60m. The basic facts need to be realised and understood.”
During a dinner at the summit last night, Mrs May criticised the EU’s refusal to share crime-fighting data with Britain after it becomes a “third country” next March, urging leaders to overcome what she sees as Brexit negotiator Michel Barnier’s uncompromising stance on the issue.
Reiterating Britain’s promise to keep providing security and defence co-operation with the EU, she added: “Consider what’s in the best interests of the safety of your citizens and mine.”