Theresa May’s chances of securing a House of Commons majority for her revised Brexit deal on Tuesday evening have been dealt a severe blow by the attorney general, Geoffrey Cox, who has concluded that the Northern Ireland backstop would still endure indefinitely if new arrangements to solve the Irish border were not reached with the EU.
In his eagerly anticipated advice — which will be crucial to the decisions of Tory Brexiteers and the Democratic Unionist party on whether to back May — Cox said that new legal assurances secured by the UK late Monday night would reduce the risk of the UK being stuck in the backstop only if it could show the EU had acted in bad faith.
"The legal risk remains unchanged," Cox wrote, where both parties were acting in good faith and were simply unable to reach an agreement because of "intractable differences".
Cox wrote in his updated legal advice: “In my letter of 13 November 2018, I advised that the Protocol would endure indefinitely in international law and could not be brought to an end in the absence of a subsequent agreement. This would remain the case even if parties were still negotiating many years later, and even if the parties believed that talks have clearly broken down and there was no prospect of a future relationship agreement.”
He said the risks would remain "if through no such demonstrable failure of either party, but simply because of intractable differences, that situation does arise, the United Kingdom would have, at least while the fundamental circumstances remained the same, no internationally lawful means of exiting the Protocol’s arrangements, save by agreement".
Rejecting the new agreement, the European Research Group's so-called star chamber of Brexiteer lawyers and MPs said the new legal advice "does not meet the tests the government set itself".
Veteran Eurosceptic MP Bill Cash said on behalf of the ERG leadership that "in light of our own legal analysis and others we do not recommend accepting the government's motion today", raising the question of whether the ERG would tell its MPs to vote against the deal or abstain.
Democratic Unionist party deputy leader Nigel Dodds also indicated his opposition to the deal. Speaking in the Commons, Dodds warned: "Provided there is no bad faith, the fact is that Northern Ireland and the rest of the United Kingdom could be trapped."
Brexiteer rebel MPs said the ERG is split on how to vote tonight. Some Eurosceptics had wanted a "ladder to climb down" so they could vote for the deal, one said, indicating that dozens could yet back the government. But the MP also said that Cox's advice and the DUP's opposition to the deal meant most Tory Brexiteers could not back the deal.
The MP said: “The ERG is torn. It’s an agonising decision to make. We wanted a ladder to climb down. We wanted a resolution.
"But Cox couldn’t have been clearer. The WA is unchanged and the risks are unchanged. Of course we fear what comes next as some MPs try to plot to reverse the referendum result.
"But we also fear betraying voters by backing the very same deal that was so categorically thrown out by 230 votes; the largest defeat in parliamentary history. I worry we’d be letting down our voters, our members, our country, if we backed this deal."
Labour said the government's Brexit strategy was "now in tatters". Responding to the publication of Cox's advice, shadow Brexit secretary Keir Starmer said: “The Attorney General has confirmed that there have been no significant changes to the Withdrawal Agreement despite the legal documents that were agreed last night."
Jean-Claude Piris, the former director general of the European Council’s legal service, tweeted that “the UK now has a legal remedy not to be trapped in a customs union”.
In a glimmer of hope for Downing Street, Irish opposition party Fianna Fáil said it was "extremely concerned" by Cox's legal advice because, they said, it suggested it was easier for the UK exit the backstop.
Separately, Lord Anderson QC — the government’s former terror legislation watchdog — and Jason Coppel QC, who produced their own legal opinion for the People’s Vote campaign overnight, said: “The backstop will endure indefinitely, unless and until superseded by another agreement, save in the extreme and unlikely event that in future negotiations the EU acts in bad faith in rejecting the UK’s demands.”
They added: “The interpretative declaration does not materially change the legal effect of the Withdrawal Agreement and the Protocol.”
Remarking on the latest developments, an EU source said: “Uh oh.”