What do George Osborne, Jeremy Corbyn and Ed Miliband have in common? A liking for a soft Brexit, it turns out.

But while Osborne is responding to the border lockdown instinct of some Tory Brexiteers, the former Labour leader, along with Chuka Umunna, Lisa Nandy and Rachel Reeves, has to start by making the case to fight for Brexit at all.

And that’s before you get to the thorny and emotional question of freedom of movement.

Speaking at a Resolution Foundation fringe event, Miliband ridiculed calls to be the “party of the 48 per cent”, in reference to the proportion who voted to stay in the EU referendum.

Remain voters should stop thinking Brexit was a “nasty accident” and start fighting for a good deal, he urged.

Miliband said: “I see talk saying we should become the party of the 48 per cent. That is nonsense.

"I don’t just think it is nonsense electorally, but it is nonsense in policy because it buys into the same problem people were objecting to in their vote which is the old ‘I’m right, you’re wrong’”.

Remain voters shared many of the same concerns as Leave voters, including on immigration, he said.

Miliband praised the re-elected Labour leader Jeremy Corbyn’s comments that a hard Brexit would be a disaster. He said: “We have to engage in these negotiations.”

Although he said he “anticipated” staying on the back benches, he did not rule out a return to the shadow cabinet, and urged the party to use its newly recruited member, many of whom joined under Corbyn.

Miliband was backed up by Nandy, seen as a rising star of the party, who said there was longterm dissatisfaction with jobs and wages: “You throw freedom of movement into the mix and you create dynamite.”

She also called for Labour to throw itself into Brexit negotiations: “We have been stuck between two impossible choices, between pulling up the drawbridge or some version of free market hell.

“But the truth is we are a progressive, internationalist, socialist party and we can’t afford to make that false choice.”

Reeves, who wrote in The Staggers that freedom of movement should be a “red line” in Brexit negotiations, said: “I don’t buy this idea that people who voted Leave have changed their minds.”

And she dismissed the idea of a second referendum on the eventual deal: “If people voted against the deal, then what?”

But while the speakers received warm applause from the party member audience, they were also heckled by an EU national who felt utterly betrayed. Her interruption received applause too.

Umunna acknowledged the tensions in the room, opening and ending his speech with a plea for members not to leave the party.

Having called identity politics "the elephant in the room", he declared: “We have got to stay in this party and not go anywhere. It is not just because you don’t win an argument by leaving the room, it is because we are the only nationwide party with representatives in every region and nation of this country. We are the only party representing every age and ethnic community.

“Stay in this party and let us build a more integrated Britain.”