THERESA May has been warned that a lengthy delay to Brexit could destroy the Conservative Party, with a minister claiming it would be a Tory "suicide note" if the UK had to fight the European elections.

The stark warning about the "seismic" changes to British politics that would be unleashed if the May 23 European Parliament elections went ahead came as the Government sought to revive talks with Labour aimed at finding a Brexit compromise.

Education Minister Nadhim Zahawi said the situation needed to be resolved quickly in order to avoid the "existential threat" posed if the UK remained in the EU at the time of the elections next month.

"It would be, I think, a suicide note of the Conservative Party if we had to fight the European elections," he said.

He said that if Labour could not sign up to a joint approach, then MPs should be forced to find a compromise through a preferential voting system in order to resolve the situation.

"We need to do that quickly because, I think, going into the EU elections for the Conservative Party, or indeed for the Labour Party, and telling our constituents why we haven't been able to deliver Brexit, I think would be an existential threat," he told BBC Radio 4's Today programme.

READ MORE: Labour walk out of Brexit talks as Theresa May refuses to negotiate

Downing Street has offered further talks with the opposition this weekend after efforts to find a breakthrough stalled, but Labour said the Prime Minister had to come forward with "genuine changes".

Chancellor Philip Hammond insisted the Government had "no red lines" in the talks and he was "optimistic that we will reach some form of agreement with Labour".

At a meeting of EU finance ministers in Bucharest, he said: "The conversations with the Labour Party are continuing, they were continuing last night, we are expecting to exchange some more texts with the Labour Party today."

Asked about the prospect of a second referendum, he said: "We should try to complete this process in Parliament, that's the right way to do it. But we should be open to listen to suggestions that others have made.

"Some people in the Labour Party are making other suggestions to us, of course we have to be prepared to discuss them.

"Our approach to these discussions with Labour is that we have no red lines, we will go into these talks with an open mind and discuss everything with them in a constructive fashion."

READ MORE: Little enthusiasm in Europe for Theresa May's plea for short Brexit delay

The talks appeared on the verge of collapse on Friday night after shadow Brexit secretary Sir Keir Starmer said the Government was not "countenancing any changes to the actual wording of the Political Declaration", the blueprint for the future UK-EU relationship.

Shadow home secretary Diane Abbott said: "We are engaged in these talks in good faith but the Government perhaps has to show a little more flexibility than it seems to have done so far."

Labour's position was that it wanted a customs union, single market alignment, protection of rights and "some kind of People's Vote".

Pressed on whether any agreement must have a second referendum attached to it, she told Today: "We are not saying anything definitively but we have a position."

While it "has to be part of the negotiations", Abbott said "we have not gone into these talks being dogmatic".

She added: "I think a People's Vote has its difficulties. I think if we had that vote tomorrow, I believe Leave would win."