Parliament is “very likely” to be given a vote on the final Brexit deal drafted by Theresa May, a Government lawyer has confirmed for the first time.
James Eadie QC told the High Court that MPs and peers will have to ratify any package hammered out with Brussels on the UK’s exit from the European Union.
“The view within government is that it is very likely that this treaty will be subject to ratification process in the usual way. Most of them are,” Eadie said.
Downing Street sources told HuffPost UK that Eadie’s remarks on Tuesday were an “accurate reflection” of the Government’s interpretation of the law.
The PM’s spokeswoman added: “It’s the position the Government has been making in court.”
The announcement raises the possibility that Parliament could reject or amend the Brexit deal if it was unhappy with key elements of the impact on trade, immigration or other areas.
But critics claimed that the new wording underlined that the Government was beginning to realise how weak its legal case was in preventing MPs from having a vote on Article 50, the formal process of leaving the EU.
And as the pound made its biggest gain since mid-August, some legal commentators suspected the sterling spike stemmed more from hints from a High Court judge that MPs should be given a say even before Article 50 is triggered.
The shift in position was unveiled on the third day of the High Court challenge against the Government by a businesswoman who is demanding that MPs be given more of a say over Brexit.
Gina Miller says that MPs should have a vote on the timing of Article 50, the process that formally begins the UK’s exit from the EU.
Government lawyers oppose the case, stressing that May is legally within her rights to go ahead with the formal process next March, using Royal Prerogative powers.
The Attorney General Jeremy Wright has argued strongly in court that the court challenge is an attempt to “invalidate” the public’s decision to quit the EU.
But today’s remarks suggest that the Government is keen to reassure Tory MPs that they will get a final say on the eventual package drafted by the Government, which is due sometime in 2019.
The PM’s spokeswoman said that the “caveats” to the court remarks were that the final shape of any Brexit deal was currently unknown.
“But there will be obligations to meet with regard to the  Constitutional Reform and Governance Act [which obliges the UK to allow Parliament to ratify international treaties rather than use Royal Prerogative powers] and we would consider the outcome against those obligations - and meet them.”
UK voters opted in favour of leaving the EU by 51.9% to 48.1% in a referendum in June.
The Government sought to avoid a Tory rebellion over Article 50 last week by suggesting MPs could at some point in the future have more of a say on Brexit.
However, some observers of the court case suggested that more significant than the Government lawyer’s remarks was the hint from the judge that he could uphold the challenge.
The complainants argue that the Government cannot use the Royal Prerogative to remove rights which Parliament has already conferred on citizens.
They argue that a new Act of Parliament would be needed to trigger Article 50 and that conditions could be applied to such prior approval - including an option that the UK remains in the EU if the Brexit deal is rejected by MPs and peers.
Shadow Brexit Secretary Keir Starmer said: “The House of Commons needs to be involved in this process from start to finish. The issues involved are simply too important for the House of Commons to be side-lined until the end.
“A vote so late in the day would put MPs between a rock and a hard place. It would ask us to choose between a deal on the government’s terms or leaving the European Union with no deal at all.”
Open Britain campaign member Tory MP Neil Carmichael said: “It’s an encouraging sign that the Government has agreed to give Parliament a say on the final terms of Brexit.
“But there must be a role of Parliament before the end of the negotiations. The best place to start would be for the Government to commit to a debate and a vote in the House of Commons on the Government’s principles for the upcoming negotiations before they trigger Article 50.”