THE European Court of Justice could continue to exercise jurisdiction over UK law during the transition to Brexit, under the terms of a new position paper published by the government.
And any new dispute resolution mechanism created to adjudicate on post-Brexit rows between the UK and EU could be required to take account of, or even be bound by, the rulings of the Luxembourg-based court.
The paper released by David Davis's Department for Exiting the EU (DExEU) ruled out any direct ECJ jurisdiction over UK law following Brexit, which ministers branded unnecessary, inappropriate and unprecedented.
It said that legal disputes involving individuals and businesses should in future be decided within the UK judicial system, with the Supreme Court as the final arbiter.
And it said a new dispute resolution mechanism – which could involve a joint committee or arbitration panel – will have to be created to deal with disagreements over the interpretation and application of the Brexit deal. The mechanism could be triggered if either side believes the other is failing to implement the terms of the agreement or has introduced legislation which breaches it.
But the DExEU document did not rule out the ECJ maintaining its authority during the transitional period, which is expected to last a number of years after the March 2019 deadline for Brexit, saying only that Britain will "work with the EU" on the design of interim judicial arrangements.
And it set out a range of existing arrangements involving the ECJ which could act as possible models for the new mechanism.
These include the EU's agreement with European Free Trade Association (Efta) states like Norway and Iceland, which demands that "due account" be paid to the court's rulings, and a treaty with Moldova, which requires an arbitration panel to be bound by its interpretation of EU law.
The DExEU document makes clear that Britain is not committed to following any of these existing models. But it does not explicitly rule out any scenario other than direct ECJ jurisdiction.
Speaking shortly before the paper's publication, Prime Minister Theresa May insisted that the UK would "take back control" of its laws after Brexit.
"What is absolutely clear, when we leave the European Union we will be leaving the jurisdiction of the European Court of Justice," she said during a visit to Guildford in Surrey.
"What we will be able to do is to make our own laws.
"Parliament will make our laws. It is British judges who will interpret those laws and it will be the British Supreme Court that will be the arbiter of those laws."
The DExEU document states that Britain's aim is to "maximise certainty" for individuals and businesses and to ensure that they can "effectively enforce their rights in a timely way", while respecting the autonomy of UK and EU legal systems.
At a press conference in Brussels, European Commission spokesman Alexander Winterstein declined to comment on the UK proposals, but said that the EU's position was "very clear, very transparent and unchanged".
The remaining 27 EU states have approved negotiating guidelines that envisage the ECJ retaining authority over the interpretation and implementation of the Brexit agreement and oversight of the treatment of European citizens in the UK.
Labour peer Lord Adonis, a leading supporter of the Open Britain campaign against a hard Brexit, said: "This is a climbdown camouflaged in jingoistic rhetoric. Even if we leave the single market, European judges will still have considerable power over decisions made in the UK.
"It would make far more sense for the government to negotiate continued membership of the customs union and single market. Otherwise, we get the worst of all worlds – a worse deal on trade and jobs than now, yet no extra control over anything for real."
Liberal Democrat Brexit spokesman Tom Brake said: "The government has produced a position paper without a clear position. No-one reading this paper will have a clue what they actually want.
"It's a desperate attempt to hold together a divided Conservative Party and prevent a rebellion among Eurosceptic backbenchers.
"Despite Theresa May's tub-thumping rhetoric, it's clear that protecting British trade, security and families will mean accepting a role for the European Court."
The Oxford Economics think tank downgraded its estimate of the likelihood of successful separation and transition agreements from 70 per cent to 60 per cent, arguing that DExEU's position papers risk making the negotiation process even harder.
"The UK has made little attempt to progress separation issues, while its ideas for transition could require yet more negotiation and risk eroding the benefits of transitional arrangements for business," the group said.
