Loyalist Tory MPs are to test whether inserting a sunset clause for the Northern Irish backstop would be a path to convincing rebels to accept Theresa May’s Brexit deal.
Andrew Murrison, the chair of the Northern Ireland affairs committee, has tabled an amendment to May’s Brexit deal – set to be voted on by MPs on Tuesday – that would prevent the backstop arrangement extending beyond the end of 2022.
The amendment would approve the Brexit deal “subject to a legal codicil being added to the withdrawal agreement treaty which specifies that the backstop solution shall expire on 31 December 2022”.
The backstop arrangement, which is the key objection of the Brexiters and the DUP, would keep the UK in an effective customs union until another solution can be found to avoid a hard border in Northern Ireland.
The EU has insisted, including in a letter to May on Tuesday, that there can be no end date for the backstop because it would then cease to be an insurance option. If Murrison’s amendment were passed by the Commons, it would amount to an ultimatum to the EU, which would then have to decide whether it could produce this codicil to make the deal acceptable to parliament.
A backstop is required to ensure there is no hard border in Ireland if a comprehensive free trade deal cannot be signed before the end of 2020. Theresa May has proposed to the EU that the whole of the UK would remain in the customs union after Brexit, but Brussels has said it needs more time to evaluate the proposal.
As a result, the EU insists on having its own backstop - the backstop to the backstop - which would mean Northern Ireland would remain in the single market and customs union in the absence of a free trade deal, prompting fierce objections from Conservative hard Brexiters and the DUP, which props up her government.
That prompted May to propose a country-wide alternative in which the whole of the UK would remain in parts of the customs union after Brexit.
“The EU still requires a ‘backstop to the backstop’ – effectively an insurance policy for the insurance policy. And they want this to be the Northern Ireland-only solution that they had previously proposed,” May told MPs.
Raising the stakes, the prime minister said the EU’s insistence amounted to a threat to the constitution of the UK: “We have been clear that we cannot agree to anything that threatens the integrity of our United Kingdom,” she added.
The amendment is unlikely to pass the Commons because it does not have Labour frontbench support, but No 10 is likely to watch to see how much support the ploy will attract. The signatories to the amendment, normally loyal Conservative MPs, have sparked reports that the plan could have tacit approval from No 10.
A Downing Street source said they expected May to be “noncommittal” about the amendment, but it is understood that MPs are not being discouraged from voting for it.
Murrison dodged a question about whether the amendment had been approved by Downing Street, saying only that he was “delighted” if it won government backing.
“The whole point of this is to get a substantial number of colleagues from right across the house to come together and say actually this is the basis of the way forward, this identifies our chief objection to the withdrawal agreement as drafted,” he told Sky News.
Murrison said the amendment would bring the agreement in line with other international agreements. “Treaties aren’t made holding countries indefinitely against their will so what it does is really normalise the treaty we are going to enter into,” he said.
The former immigration minister Robert Goodwill, who has signed Murrison’s amendment, said the key aim of the text was to give the DUP reassurances and Tory colleagues “a rope ladder to climb down”.
“This is not so much about Downing Street, it’s about the DUP,” he said. “If Nigel Dodds and his colleagues agree that something like this would satisfy their concerns about the backstop, and then if they vote for a revised deal, it is very hard for the ERG to say they still have issues. A lot of other Tories would have to snap into line.”
Goodwill said that many Tories who had resigned or stated publicly that they would not back the deal needed to be given a way out, but he said he had no anticipation that that would happen by tomorrow night.
“Once we get through tomorrow night, they may show a bit more flexibility,” he said. “If someone’s resigned because they don’t like the deal, it would be very difficult for them not to vote against it this time round. They are keen to come back into the fold and support a deal that will deliver on Brexit rather than a situation where we could see the perfect be the enemy of the good.”
Goodwill said he hoped the amendment would be a starting point for “something that emerges that is even more concrete than the amendment which could be reassuring to people”.