Parliament will get a vote on the final Brexit deal before the UK leaves the EU, minister David Davis has told MPs.
He said the terms of the UK’s exit, including details on money, citizen rights and transition would have to become law via a new Act of Parliament.
While any deal “will only hold” if MPs approve it, he said it would not alter the fact the UK was leaving the EU.
Labour welcomed the “climbdown” but some MPs queried whether any vote on a last-minute deal could be “meaningful”.
The BBC’s political editor Laura Kuenssberg said the announcement was significant because it represented a big concession to potential Tory rebels and Labour MPs at a highly important moment in the Brexit process.
It comes as MPs prepare to debate key Brexit legislation later this week with the government facing possible defeat on aspects of the EU Withdrawal Bill, which will convert EU law into UK law.
The UK is due to leave the EU in March 2019, irrespective of whether MPs back or reject the terms of the deal negotiated by Theresa May’s government.
Updating MPs on the sixth round of talks which concluded on Friday, Mr Davis told MPs that they would play a major role and “there cannot be any doubt that Parliament will be intimately involved at every stage”.
The government had previously agreed to give MPs a vote on a Commons motion relating to the final Brexit deal – before it has been voted upon by the European Parliament.
Mr Davis said he still “intended and expected” this to happen but went further – agreeing to Labour and Tory MPs’ demands for any vote to take place on substantive primary legislation.
The bill, he told MPs, would contain the contents of the withdrawal agreement that the UK hopes to seal in time ahead of its scheduled departure and all key aspects of it – such as the financial settlement between the two sides, the future status of UK and EU citizens and the terms of any transition.
“This means that Parliament will be given time to scrutinise, debate and vote on the final deal we strike with the EU,” he said, adding that it was not clear when such a bill would be published.
Labour welcomed a binding vote on a specific exit bill but said it could not mask the fact that there had been a “profound lack of progress” in the negotiations to date.
“This is a significant climbdown from a weak government on the verge of defeat,” shadow Brexit Secretary Sir Keir Starmer told MPs.
“For months, Labour has been calling on ministers to guarantee Parliament a final say on the withdrawal agreement.
“With less than 24 hours before they had to defend their flawed Bill to Parliament, they have finally backed down. However, like everything with this Government, the devil will be in the detail.
“Ministers must now go further. They need to accept Labour’s amendments that would ensure transitional arrangements, and protect jobs and the economy from a cliff edge.”
Several Tory MPs questioned what would happen if a deal was only agreed at the last minute before the 29 March exit – a scenario which Mr Davis has suggested was conceivable.
Antoinette Sandbach pressed Mr Davis to reassure MPs how “if the bill intended to ensure a meaningful vote only comes forward after that date, the vote is in any sense meaningful”.
Mr Davis responded by saying it would give MPs the opportunity to say “either you want the deal or you don’t want it”.