Theresa May has refused to back down ahead of a possible defeat on the Brexit Bill tonight, insisting it would put a “smooth and orderly” withdrawal in jeopardy.

Giving way to Tory rebels - in a crucial vote that could give MPs the power to delay Brexit – could leave confirmation of withdrawal until “a very late stage”, the Prime Minister said.

“That could mean we cannot have the orderly and smooth exit from the European Union that we wish to have,” she told MPs.

Anna Soubry, a leading rebel, had urged Ms May to give way and grant MPs a truly “meaningful vote”, in a clash on the EU Withdrawal Bill on Wednesday evening.

Amendment 7 is designed to give MPs a binding decision on the terms of Brexit – with the potential to delay withdrawal, if no satisfactory deal has been reached.

The Prime Minister has already conceded to MPs a vote on the final Brexit deal and a Bill to follow, which could be amended.

However, she has insisted it will be a “take it or leave it” offer – meaning the UK would crash out of the EU without a deal in March 2019, if hers is rejected.

Ms Soubry urged Ms May to recognise that Dominic Grieve, who has tabled the amendment, is a loyal Conservative and a reluctant rebel, urging her to accept it in a “spirit of unity”.

But the Prime Minister insisted a meaningful vote is “what we will have”, insisting it would take place well before March 2019 withdrawal date.

Around 20 Conservative MPs, including former Cabinet ministers Ken Clarke and Nicky Morgan, are expected to back Mr Grieve’s amendment 7.

That is more than enough to defeat the Conservatives’ working majority of just 13 – unless the rebels fold under heavy arm-twisting from Tory whips not to give Ms May “a bloody nose”.

The amendment would prevent the Government using statutory instruments to enact withdrawal, which would bypass MPs even if they reject the deal the secured.

It would stop that enactment until Parliament has voted in favour of a separate Bill, which could be amended, perhaps to keep the UK in the EU single market and customs union.

In her answer, Ms May stuck to the Government’s stance that the vote would take place on a motion – before that Bill is put forward – which is unlikely to weaken the rebels’ resolve.

She told MPs: “What the amendment says, is that we shouldn’t put any of those arrangements, any of those statutory instruments, into place until the withdrawal agreement and implementation bill has reached the statue book.

“That could be at a very late stage in the proceedings, which could mean that we are not able to have the orderly and smooth exit from the European Union that we wish to have.”

But defeat tonight would inflict huge damage on the Prime Minister, raising fresh fears in EU capitals that she is too weak to deliver on her Brexit promises.