UK Prime Minister Andy Burnham faces pressure to commit Labour to rejoining the EU after he promised to look at all options for a closer relationship with the bloc.
In his speech to the Labour Party conference today, the Mr Burnham said Brexit had done "more harm than good" and called for Britain to consider its "long-term relationship" with the EU.
He announced that he would use the UK-EU summit expected later this year to set out what he believed were the "different options" and attempt to find a political consensus on a way forward.
Responding to the prime minister's speech, Labour MP Stella Creasy said "everything must be on the table", including removing the "red lines" set down in the party’s 2024 manifesto that bar rejoining the EU’s single market or the customs union.
She said: "Removing the red lines on Europe is the essential first step to restoring this country’s place on the world stage.
"We stand with this Prime Minister in making the changes that truly live up to the challenges of 2026, not 2016."
In his speech in Liverpool, Mr Burnham said the UK has "lost some control" over the economy and immigration as a result of leaving the EU.
He said: "We will not give Britain the clear path we need into the rest of the century until we decide on a long-term relationship with what is still our largest market.
"I cannot say to you that where we are is good enough. Brexit has done more harm than good."
A UK-EU summit scheduled for July was postponed after the resignation of Keir Starmer, and a new date has yet to be decided.
Criticising Brexit, Mr Bunrnham said: "Brexit hasn’t given us control. We’ve lost some of the control we had over our economy, as a decade of low growth has put us in a weaker position. And we’ve lost some of our control over immigration.
"At its most fundamental level, this is a debate about fairness. So I understand the anger about what is happening in the Channel.
"Shabana (Mahmood) has done a great job in beginning to restore our grip over the system."
He continued: "We make these changes while always grateful to those who have come here and are contributing to our country.
"But control over immigration was weakened when we lost collaboration with our European partners and we are still having to work hard to bring it back."
Cabinet minister Heidi Alexander said "no-one wants to go back to the toxicity and divisions" of the Brexit debate, "but you can't have a conversation about the future of this country and not address this question".
At a Politico fringe event in Liverpool, the Transport Secretary said: "I think he’s right to say we need to set out the options.
"But he was also pretty clear at saying we need to develop some consensus around this.
"No-one wants to go back to the toxicity and the divisions of previous Brexit debates.
"The world is changing. Europe’s changing. You saw those conversations that Canada and Mark Carney were having.
"And so, look, let’s take our time on this. We need to respect the red lines that were set out in the manifesto. And I think it is really important for trust in politics that we don’t breach the trust of the British people.
"But you can’t have a conversation about the future of this country and not address this question."
Naomi Smith, chief executive of Best for Britain, said Mr Burnham should go further and pledge to re-join the bloc.
She said: "Our best-in-class, seat-level polling resoundingly demonstrates half-measures on Europe won’t deliver a Labour-led government at the next general election, or protect us from the waking nightmare of prime minister Nigel Farage.
"We said it needed to be a deafening alarm bell to every slumbering Labour MP and snoozing No 10 strategist. Burnham’s speech today proves he’s wide awake – and alive to the dangers.
"It’s vital the Labour government seizes this moment, not in 2029 or a year, or six months’ time.
"With the public behind him, progressives imploring them, and the economic case etched in stone, we should signal to the EU – today – that the UK is ready to apply for membership, to take us back to where we belong at the heart of Europe."
Conservative deputy leader Alex Burghart said: "Andy Burnham came to office with no plan to tackle the challenges facing our country. So instead, he is trying to reopen old wounds by restarting the battles of the Brexit years.
"Labour cannot pin the blame for their disastrous economic decisions on a vote that happened over a decade ago. Besides, they are already dragging us into the European Union via the back door with their EU reset."
Burnham vows electoral reform, reversal of privatisation, free social care
Mr Burnham also promised greater public control over essential services as he vowed to reverse decades of privatisation and rebuild Britain.
The 56-year-old former mayor of Manchester - in office for just 10 weeks - choked back tears as he spoke about his late father and detailed his long-term ambitions to establish free social care, reform the UK's electoral system and controversially adjust pensions.
"I accept people will not agree with every part of it, but I believe it can turn Britain around," Mr Burnham said.
At one point he had to pause, swallowing tears before he talked about his father who died earlier this month from Alzheimer's.
"I'm going to use this job to build the kind of Britain my dad wanted to see and fight with everything I've got to keep it together."
He then launched into an impassioned defence of his plans to introduce free social care in England for people who need help living with illness or disabilities.
"I accept I may pay a political price. But someone has to go through the pain barrier and rip the plaster off," he said, acknowledging the difficulties of introducing a new system.
Mr Burnham told Labour MPs and activists that greater public control over housing, energy and water, coupled with more powers for local leaders, would help spur Britain's struggling economy.
"I will make a break with the direction of the past 40 years and put Britain on a new path, build a new economy and a new politics," said Mr Burnham, the UK's seventh prime minister in a decade.
He said his government would soon introduce a bill to repeal 1979-1990 prime minister Margaret Thatcher's "ideological ban on public ownership of water companies".
He vowed to build a "National Care Service" that would be "free at the point of use", although not until after the next general election, expected in 2029.
To pay for the plans, Mr Burnham said he would campaign at the next election on changing how pensions rise, a bold move that right-wing parties immediately labelled as an attack on the elderly.
"By potentially scrapping the triple lock, Andy Burnham will abdicate his responsibility to British pensioners," said Nigel Farage, leader of the anti-immigration Reform UK party.
Since becoming prime minister on 20 July, Mr Burnham has sought to offer a more optimistic tone, strengthening his friendly public image.
Labour's conference slogan is 'Hope Again' and delegates are more upbeat than in the past two years when recriminations flew over several policy U-turns.
But a new YouGov poll Tuesday showed the party had slipped back behind rival Reform, which had 25% of voting intentions to Labour's 24%.
Mr Burnham also announced radical plans for electoral reform that could pave the way for proportional representation.
Labour will fight the next election on a promise to change the existing first-past-the-post system so that "everyone's vote counts and everyone’s voice is heard", he said.
A new national commission will be set up to explore reforms, with all political parties invited to be a part of its work, he told the party’s annual conference.
