Theresa May’s preferred customs model is flawed, “deeply unsatisfactory” and would keep the UK tied to the single market, MP Jacob Rees-Mogg has said, urging the prime minister to ditch the proposal at a crucial Brexit cabinet meeting on Wednesday.
A group of 60 Eurosceptic MPs from the influential European Research Group, led by Rees-Mogg, have sent May a 30-page report opposing the prime minister’s plan for a “customs partnership” model, one of two options on the table at the Brexit cabinet subcommittee meeting.
Rees-Mogg said the letter sent to May was “not an ultimatum” from Eurosceptic MPs, but would not commit to backing the plan should it be put to parliament as part of the final Brexit agreement.
Pro-Brexit ministers will attempt at the 11-strong cabinet subcommittee meeting on Wednesday to get May to drop her preferred option for a so-called hybrid model, under which the UK would collect EU import tariffs on behalf of Brussels and then refund any companies when the goods’ end use is not in the EU27.
Brexiters believe the model is complex and ultimately unworkable, opening the door to remaining in a customs union, while the plan’s backers believe it would solve the Irish border question and still allow Britain to strike trade deals.
It may also head off a parliamentary rebellion in which pro-remain Tories side with Labour to keep the UK in a full customs union.
The letter from Rees-Mogg and the ERG claims the plan would “festoon the entire economy with burdensome controls, while crippling the ability of the UK” to negotiate trade deals. Tory sources told the Telegraph the group has threatened to withdraw support for the government if the plan is pushed through.
Rees-Mogg said the report should not be seen as a threat to May’s position. “I am neither John Wayne nor James Stewart. That is not the way we would behave towards the prime minister. There is no question of this being an ultimatum,” he said.
Rees-Mogg said the plan would not deliver on the Conservative party manifesto or to other commitments made by the prime minister.
“This customs partnership is one of those clever ideas that sounded plausible when first looked at and when the detail is examined turns out to be deeply unsatisfactory, flawed and not get us out of the European Union, which is what people voted for.”
Instead, Brexiters in the cabinet hope to persuade the prime minister to keep the other alternative on the table for now – the maximum facilitation (“max-fac”) proposal, which relies on technology and a “trusted trader” scheme to minimise border checks.
Crucial to the decision will be new home secretary, Sajid Javid, and the defence secretary, Gavin Williamson, whose interventions are likely to tip the balance of the committee.
Javid, a more natural Eurosceptic who said he voted remain “with a heavy heart”, replaced Amber Rudd on the committee, who had been at the heart of the cabinet caucus pushing for a softer exit, alongside the chancellor, Philip Hammond, and the business secretary, Greg Clark.
Williamson told an audience at the Institute of Economic Affairs on Tuesday night that it was “not the time to be timid or go into retreat”.
The customs partnership has become the most contentious issue in the debate about what kind of Brexit should be pursued, with many MPs regarding it as the only way of successfully avoiding a hard border in Northern Ireland.
Brexiters in the cabinet including David Davis, Boris Johnson and Liam Fox are expected argue that maintaining the integrity of the Good Friday agreement does not mean no infrastructure whatsoever between Northern Ireland and the Republic.
Shadow Brexit minister Paul Blomfield said the report from the ERG was “further evidence that Theresa May is being held hostage by the extreme Brexiteers in her own party.
“Crunch time is coming on what our future customs arrangements with the EU should look like. The Tories appear more interested in issuing ultimatums and squabbling amongst themselves than acting in the national interest.”
May will ultimately be the deciding voice on the committee. The prime minister’s official spokesman said: “We have been absolutely clear that we are leaving the customs union and won’t be joining a customs union.
“We have put forward two proposals for addressing the customs issue in general and they will be discussed by the government further.”