Keir Starmer is under mounting pressure from Labour MPs in Brexit heartlands to back a trade deal with the EU.
Negotiations to strike an agreement with Brussels are continuing this week as the deadline for a pact narrows.
If a deal is reached, it would force Labour to choose whether to support or oppose it in the Commons – or simply sit on the fence.
Backing a pact would trigger claims in Remain-leaning seats that the party had sided with Boris Johnson over Brexit.
But symbolically trying to block an agreement – which would win parliamentary support anyway because of the Tories' 80-seat majority – would unleash fresh claims the party had failed to learn the lessons of the 2016 referendum and last year's humiliating election defeat.
Labour chiefs are understood to be ready to order MPs to vote for any agreement struck with the EU.
They want to frame the choice as between voting for a deal or no-deal, which would worsen the economic damage caused by Covid-19.
A Labour source said: “We have left the EU and the Leave/Remain divide is over.
“What the British people want to see is this issue put to bed so we can focus on rebuilding from the pandemic.
“The new leadership is clear that we must be a part of that process, accepting we need a deal and focusing on how we rebuild from this pandemic with a positive vision for the future.”
Backbencher Jon Trickett, a former Shadow Cabinet Office Minister who is MP for Hemsworth, West Yorks, told the Mirror: “We should vote for it providing it's not a completely outrageous deal.
“However, we've got to put some markers down because a Brexit deal on Boris's terms may well be very, very bad for the North of England and other parts of the country too which are already falling behind.
“What I want is Labour to demand a Brexit which works for every single part of the country. It comes down to massive regional investment and state aid.”
He called for a pact which “looks after the communities which voted for Brexit rather than abandons them” and believed backing a deal could be key to rebuilding the red wall of constituencies in the Midlands and North – traditional Labour strongholds which elected Conservative MPs at last December's ballot, Labour's worst defeat for 84 years.
“Every single opinion poll I have seen still puts Labour behind among people who voted Leave – and well behind,” he said.
“Many of those are people who come from communities which voted Labour for generations so we have to show that we've understood the message – once in the referendum and the second time in a general election.
“The message is clear – they want us to accept democracy and the votes of the people.
“People have got long memories.
“There are literally hundreds of thousands of people who want to vote Labour, but this is seen as a test for us and I think we have to do it.”
Mr Trickett said it was particularly important for Mr Starmer to be seen to back a Brexit deal because as Shadow Brexit Secretary under Jeremy Corbyn he “very much” led the fight for another EU vote.
“He obviously is the most closely-associated person with the second referendum which did us massive damage in the election,” said Mr Trickett.
“I don't know about him personally but the Labour Party needs to effectively give an apology both to Leave voters who feel they were betrayed and to Remain voters who thought they were on a promise and now suddenly discover we are likely to be voting for Brexit.
“We have to be clear – tell the story and give an apology so we can get a hearing on other matters.”
MP Liam Byrne, who is bidding to become Labour's first Metro Mayor for the West Midlands, said: “We have got to take out the Tory mayor in the West Midlands next year and that's going to be much harder if we don't support a deal.
“Going forward, we have got to win seats in places like Walsall, Sandwell, Dudley – and that task is going to be much harder if we set our face against pushing through the decision the country ultimately voted for.”
He believed Labour-supporting Remainers would “understand” the position because “they know that this is the end of the road and they know the country has now got to move on”.
He also stressed a deal which emerged would, by definition, have the EU's approval.
One Shadow Minister said: “It maybe that we put a peg on our nose and vote for this deal.
“I don't think abstaining is a realistic alternative.”
The frontbencher said it was “absolutely vital” for Labour not to “be seen as blocking Brexit – it's done, we've left the European Union, we can't go revisiting that”.
They added: “We've got to find a way of moving on and that is why I am of the view that, distasteful as it maybe to many people, we will have no option other than to vote for the deal that comes.”
The Shadow Minister hoped “people who felt pained at, as they saw it, having to vote Tory at the last election – maybe some of them will come back to us”.
But they added: “We can't take that for granted. But they won't come back to us if we dig our heels in and say, 'No'.
“There's not a prayer of them coming back because they will just turn around and say, 'You're still not listening, we told you, we've left the EU and you're still not listening'.
“We're not going to do that.
“We are listening, we are hearing them and that's why we have to do this deal, vote for it and move on.”
A Labour spokeswoman said: “The Conservatives need to get a grip on the negotiations and deliver the trade deal they promised the British people at the last election.
“We have consistently said that no-deal would be the worst possible scenario, especially with workers, families and businesses already under so much strain from the pandemic.
“Labour will look carefully at the detail of any deal if and when it is agreed.”
