Jeremy Corbyn’s Shadow Brexit Secretary is demanding that Theresa May drop her “unhelpful” commitment to ending the jurisdiction of the European Court of Justice over Britain once it leaves the EU.

Brussels officials are insisting that the ECJ or another external court should remain the supreme court for EU migrants in Britain even after Brexit, without powers to demand “a lump sum or a penalty payment” from the British Government.

With respect to the ECJ in particular, critics are suggesting that this is like Britain demanding that British courts have the final say on the affairs of British nationals in the EU, with even former ECJ justices criticising the EU’s stance as “imperialism“.

The Government have so far held a firm line – but the opposition Labour Party seem keen to preserve the ECJ’s authority.

“We reject the ideological and deeply unhelpful red line the prime minister has drawn that would prevent any future involvement of an EU-UK court-like body, even when such an arrangement is demonstrably in the national interest,” announced Shadow Brexit Secretary Sir Keir Starmer, in a letter to the studiously europhile Financial Times co-signed by Shadow Health Secretary Jonathan Ashworth.

The former barrister said Labour wanted “a more flexible approach that would make it far easier for Britain to stay inside common EU arrangements that benefit the UK.”

As well as continued jurisdiction for the EU and membership of bodies such as Euratom and the European Medicines Agency, Starmer has hinted that this may include something very like membership of the Single Market, with its associated Free Movement immigration provisions.

“We must have immigration that works for our communities and our economy [and] that means there has to be movement of people to come and work in this country,” he said shortly before the General Election, and just hours after appearing to concede that ending Free Movement would have to be a “red line” in Britain’s negotiations with Brussels.

He now claims that he is once again “attracted to Free Movement of Labour” because, in his view, “It is important to strip out refugees and students, who should not be included in the [immigration statistics], and that leaves you with families and people who want to come here to work.

“I think we could strike a model that deals with people who want to come here to work but it has to work for the economy,” he concluded.

This is despite having went to the polls promising that “Freedom of Movement will have to end” prior to the June 8th snap election.