Theresa May was desperately trying to win over Tory rebels to night by offering them a veto on the Irish backstop.
With just five days to go until the crunch vote on her Brexit deal, the Prime Minister held private talks with sceptical Brexiteers to try and avert a crushing defeat.
It came as the Government was forced to publish legal advice it tried to keep confidential, which confirmed the UK would be unable to quit the backstop without the EU’s permission.
The backstop keeps Northern Ireland in a customs union to avoid a hard border on the 310-mile frontier with EU member Ireland.
The Democratic Unionist Party, which props up Mrs May’s fragile government, launched a furious attack on the “devastating” advice.
Nigel Dodds, the Northern Irish party’s Westminster leader, said: “The union of the United Kingdom is non-negotiable”.
In a sign of how poor relations are between the two parties, the DUP suggested their 10 MPs would be willing to back Mrs May in a no-confidence vote only if MPs first voted down her Brexit deal. Yet Downing Street claimed the Tory-DUP deal was still in place and that Northern Ireland would get the full £1billion they had been promised.
And whips are still concerned her premiership could come crashing down if Tory Brexiteer MPs support Labour in a confidence vote.
Mrs May wants to broker a compromise plan to get rebellious MPs to back her which could include giving them a parliamentary “lock” on the backstop.
It would mean the Government’s insurance policy to avoid a hard border with Ireland if a trade deal is not struck would only come into force if MPs approved it.
A No10 source said: “She understands people still have concerns and will be talking to colleagues.”
Chief whip Julian Smith was despatched to a meeting of the hardline ERG group of Brexiteers to try to win them over. But with more than 100 Conservatives now stating that they are going to oppose the Government, the scale of the challenge looked insurmountable.
MPs dismissed her “lock” proposals as a fig leaf. Former Brexit minister Steve Baker said: “It’s a silly idea few will fall for”.
Brussels appeared to be preparing for Mrs May’s deal being voted down by putting Article 50, which triggered Brexit, on the agenda of next week’s EU summit.
It raised speculation that leaders might delay the UK’s departure date to July, in order to give Mrs May more time.
The six-page legal advice by Attorney General Geoffrey Cox QC said the UK could become mired for years in negotiations with Brussels with no power to leave. The EU could apply to an arbitration panel for Northern Ireland to remain in the EU customs area after Great Britain left, Mr Cox advised.
Despite assurances the backstop, if used, would be temporary, the situation would “endure indefinitely” until a trade agreement was reached.
Mr Cox admitted it “does not provide for a mechanism that is likely to enable the UK lawfully to exit the UK-wide customs union without a subsequent agreement”. He warned the risk was “a political decision for the Government”.
Mrs May insisted both she and Mr Cox had openly said the backstop was indefinite without a final trade deal.
Mr Dodds said his party’s opposition to the deal had been vindicated.
“The legal advice just published proves Northern Ireland would be in full European Union Customs Union while Great Britain is not,” he said.
“This backstop is totally unacceptable to unionists and it must be defeated and arrangements renegotiated that uphold the commitments which the Prime Minister and her Government made.”
Blasting the attempt to keep the advice secret, Shadow Brexit Secretary Sir Keir Starmer said: “All that this advice reveals is the central weaknesses in the Government’s deal. It is unthinkable it tried to keep this information from Parliament and the public before next week’s vote.”
Meanwhile, Labour MPs were surprised that Jeremy Corbyn opted not to attack Mrs May on Brexit at Prime Minister’s Questions following one of the most turbulent days of her premiership.
And Unite General Secretary Len McCluskey, one of the Labour leader’s closest allies, dealt a blow to second referendum campaigners by suggesting voters would see it as a betrayal.
- The UK faces a new year recession as Brexit fears crush business and consumer confidence, economists predict. Chris Williamson, of IHS Markit, said: “The possibility of no deal has caused companies and customers to cancel spending.”