A “PANICKED” David Davis has performed a massive climbdown and promised MPs a vote on the final Brexit deal.

The Tory leadership are worried the Bill, which comes back in front of the Commons today, could be defeated, after backbench rebels supported an amendment from Dominic Grieve, the former attorney general, calling for a “meaningful vote”.

There were audible gasps when Davis told the Commons of the Government’s change of heart, though there were questions over exactly what was being promised.

“It is clear that we need to take further steps to provide clarity and certainty both in the negotiations and at home regarding the implementation of any agreement into United Kingdom law,” Davis said. “This agreement will only hold if parliament approves it.”

That effectively means parliament must back the Government’s deal, or seemingly accept a no-deal Brexit.

There was confusion over when the vote would be held.

Theresa May has proposed writing the Brexit date of March 29 2019 into law. Unless the vote came before then, MPs argued, Davis’s offer was meaningless.

And if the government fails to secure a deal there will be no vote.

“We can’t have a withdrawal deal Bill if there is no Withdrawal Bill,” Davis told one Tory backbencher.

The SNP’s Europe spokesperson Peter Grant said the offer had left MPs confused. “This latest move by David Davis is a panicked concession to appease Tory rebels,” he said.

“There must be an urgent clarification on the impact this new legislation will have on the EU Withdrawal Bill coming this week – it would seem parts of the Bill are now redundant with this new legislation being announced. This last-minute move shows how hopelessly divided the Tory party is, and the lack of confidence the UK Government has in itself to make a success of Brexit.”

Labour’s Chris Leslie, who supports the Open Britain campaign against a hard Brexit, called it a “sham”.

“Ministers need to do much better,” he said. “It is crucial that this meaningful vote takes place well before we leave; that defeat for the Government’s legislation will not imply leaving the EU with no deal; and that parliament has the same role in the event of a disastrous ‘no deal’ outcome.”

The Government climbdown comes ahead of a meeting between May and Nicola Sturgeon today.

Because the Withdrawal Bill legislates in areas normally devolved, the Welsh Assembly and the Scottish Parliament will be asked to give it “consent”.

Both Sturgeon and her counterpart in Cardiff, Carwyn Jones, have indicated they will recommend to their parliamentarians to refuse it.

Though that would not stop or derail Brexit, it would mean the Prime Minister having to override the opinions of the devolved parliaments, creating a constitutional crisis.

May’s team have said they will do all they can to get the consent of the two parliaments.

It will be the first time May and Sturgeon have been face to face discussing Brexit since the Tory leader triggered Article 50 in March.

Though the pair will primarily discuss Brexit, it is understood they will also talk about the Budget and the sexual harassment scandal.

A Scottish Government spokeswoman said: “The First Minister will be seeking clarity on a range of issues at this meeting with the Prime Minister, including Brexit and the impact on Scotland of the EU Withdrawal Bill.

“She will also set out the Scottish Government’s expectations of the UK Budget, as well as discussing the introduction of Universal Credit and the effect it has had.”