A senior Tory MP says he would welcome a delay in next week’s Commons Brexit vote, if it would help address concerns over the controversial backstop.
But Tory backbench chairman Sir Graham Brady said getting “clarity” on the issue was more important than “timing”.
It comes after reports that Theresa May was being urged to postpone the vote, which she is widely expected to lose.
Dismissing those reports, a No 10 spokesman said: “The vote will take place on Tuesday as planned.”
The withdrawal deal negotiated between the UK and EU has been endorsed by EU leaders but must also be backed by the UK Parliament if it is to come into force.
MPs will decide whether to accept it next Tuesday, but dozens of Tory MPs are expected to reject it, as are the DUP MPs, whose support keeps Mrs May’s government in power.
Many MPs have expressed concerns about the backstop mechanism, which is designed to stop the return of a physical border on the island of Ireland.
It would mean Northern Ireland staying aligned to some EU rules, which many MPs say is unacceptable. The UK would also not be able to leave the backstop without EU agreement.
On Thursday, Mrs May suggested MPs could be “given a role” in deciding whether to activate the backstop – but told the BBC there could be no deal with the EU without it.
But the Telegraph reported that she was being urged to delay the vote by ministers.
Asked if the PM should delay the vote, Sir Graham, who chairs the 1922 Committee of Conservative backbenchers, told the BBC’s Newsnight: “I think the most important thing is to have clarity about how we might remove ourselves from a backstop, Northern Ireland protocol situation if we were to enter into one in the future.
“It’s having the answer to that question of substance that is most important, not the timing.
“So if that question can be answered in the course of the next few days, then all well and good.
“If it can’t then I certainly would welcome the vote being deferred until such time as we can answer that question.”
On Thursday, the Labour former prime minister Tony Blair, speaking at a journalists’ lunch in Parliament, said the prime minister was facing the prospect of “hitting a brick wall at speed” on Tuesday.
Asked if she should pull the 11 December vote, Mr Blair said: “Personally, I don’t see what the point is in going down to a huge defeat.”
The government is considering an amendment to next Tuesday’s vote motion that would give Parliament more say over the backstop.
One possible option would see Parliament having a role in deciding whether to extend the transition period or enter the backstop arrangement, if no trade deal has been reached by the end of December 2020.
Will May’s suggestion win over any Brexiteers?
By Laura Kuenssberg, BBC political editor
What Theresa May sketched out on Thursday was the idea of allowing MPs to choose when and if they want to go into the controversial backstop – the insurance policy against a hard border on the island of Ireland.
Clearly, to try to get some angry Brexiteers to change their minds, the PM is trying to give a sense that they might have more of a say.
They could, as the agreement already suggests, just extend the “transition period”, giving the two sides longer to come up with a free trade deal that would mean the dreaded backstop is never used.
It’s not surprising that MPs would have a vote on that. But No 10 clearly hopes it will give some grumpy MPs a sense that they will have more of a say, introducing another layer of decision-making so that the backstop can be avoided.
The prime minister’s suggestion that changes could be made to the backstop to give MPs a role were rejected by Tory MPs on both sides of the debate, who said it was “cosmetic” and unlikely to be effective.
The PM did gain one supporter, however, when Eastbourne MP Stephen Lloyd announced he was quitting the Liberal Democrat group in the Commons to vote for her deal.
Conservative Sir Nicholas Soames has also spoken up for the PM’s deal, on the third day of debate about it in the Commons, which is focusing on the economic impact.
Ministers are arguing that Mrs May’s deal creates a unique partnership with the EU, while Labour insists it will make people poorer.