Jeremy Corbyn would be prepared to back a second referendum on the European Union if activists at his party conference forced a change in Labour policy.
But the Labour leader insisted he was not calling for a public vote and believed a general election would be a better way to resolve the political crisis over the nature of the UK's departure from the EU.
His comments came as a poll found 86% of Labour members think voters should have the final say on the outcome of Brexit negotiations, and 90% would now vote to remain in the EU.
As Labour's conference officially begins in Liverpool on Sunday, a march of MPs, MEPs, union leaders and activists will attempt to put pressure on the party to throw its weight behind a so-called People's Vote.
More than 100 constituency parties have submitted motions calling for the issue to be put to a vote.
Many activists believe that with Theresa May's plans in disarray following the rejection of her Chequers proposals by EU leaders in Salzburg, the time is now right for Labour to call for a fresh ballot.
Mr Corbyn told the Sunday Mirror: "What comes out of conference I will adhere to.
"But I'm not calling for a second referendum. I hope we will agree that the best way of resolving this is a General Election.
"But I was elected to empower the members of the party.
"So if conference makes a decision I will not walk away from it and I will act accordingly."
There was a similar message from deputy Labour leader Tom Watson, who told The Observer: "Jeremy and I were elected in 2015 to give the Labour Party back to its members.
"So if the people's party decide they want the people to have a final say on the deal, we have to respect the view of our members and we will go out and argue for it."
However, speaking to BBC Breakfast, shadow housing and communities minister Andrew Gwynne stopped short of repeating his bosses' support for a people's vote if it is the wish of party members.
"Of course we're a democratic party, but before we get that we want a general election, because this government has made a complete fist of Brexit, they haven't been able to negotiate a deal," he said.
"Ultimately we are not in control of this process right now. We want to be in control of that process. We want to negotiate a Labour Brexit."
A YouGov survey of more than 1,000 Labour members for The Observer found 86% support a referendum on the outcome of Brexit talks, against just 8% who oppose it.
Even in the North and Midlands, where many Labour constituencies voted Leave in 2016, there was overwhelming support - 86% and 88% respectively - for a second vote.
Some 81% believe their standard of living would get worse after Brexit and 89% said it would be bad for jobs.
Tory chairman Brandon Lewis said: "The last pretence that Labour ever respected the democratic decision of the British people is rapidly disappearing."
As Labour's gathering began:
- The party announced plans for a £560 million tax on holiday homes in England to fund measures to tackle homelessness and inequality
- Mr Corbyn said his government would require businesses employing more than 250 people to reserve one-third of seats on boards for representatives of their workforce
- Delegates will vote on changes to the way the party elects its leader
At Labour's women's conference on Saturday, the party faced a fresh row after a frontbencher praised the Militant-dominated council which ran Liverpool in the 1980s.
Dawn Butler hailed the example of left-wing former councillors who set an illegal budget in 1985 in protest at cuts to central government funding.
Her comments were criticised by senior peers and fellow MPs in a further indication of the divisions within the Parliamentary Labour Party.
Ms Butler said: "We are in Liverpool, where over 30 years ago the council stood up to Thatcher and said better to break the law than break the poor."
The comments revived memories of the party's battles of the 1980s, when then leader Neil Kinnock denounced "the grotesque chaos of a Labour council - a Labour council - hiring taxis to scuttle round a city handing out redundancy notices to its own workers".
His intervention was a key moment in the drive to break the far-left Militant group's hold over parts of the party, which ended with the expulsion of figures including Liverpool council's deputy leader Derek Hatton.
Shadow equalities minister Ms Butler's comments were criticised by fellow Labour frontbencher Baroness Thornton.
She said she was "surprised" Ms Butler praised a council that "issued redundancy notices to their own public sector employees, and failed to protect services too".
Fellow Lords frontbencher Lord Kennedy retweeted Lady Thornton, adding: "Well said."
Ms Butler's remarks were "far from what we should be standing for as a party", one Labour MP told the Press Association.
A Labour spokesman said: "The point Dawn was making was that like the Thatcher government of the 1980s, this Tory Government has prioritised tax cuts for the rich while cutting services like women's refuges that save lives and keep women safe."