The support of the main opposition party would be a major boost to campaigners for a second vote on Brexit.
Ever since the United Kingdom voted in 2016 to leave the EU, Labour has said it will respect the result - but it wants a closer relationship with the bloc than the one that Prime Minister Theresa May's Conservative government is seeking.
A caller lost his temper with the Labour front bench for "changing their stance" on Brexit and the idea of a second referendum.
Malta's prime minister on Thursday (20 September) signalled unexpected support from European Union leaders for a second referendum on Brexit in Britain, boosting a growing campaign for a new poll despite the British government's trenchant opposition.
He said his party was ready to "put our case to Parliament" for an early poll in comments likely to fuel speculation that Labour will table a vote of no confidence in Theresa May if talks with Brussels fail.
"The sheer levels of animosity that exists between Corbyn and his opponents is quite remarkable", Anand Menon, political professor at King's College London, told AFP ahead of the four-day event in Liverpool.
A crowd waving European Union and other flags chanted "bollocks to Brexit" and "it's not a done deal" as they walked from St George's Hall to a rally at Pier Head, close to where the conference is taking place.
BBC political correspondent Iain Watson said the final wording of any motion would be crucial and that Mr Corbyn would be hoping it did not tie his hands - but that some members would be pushing for a clear commitment to a new referendum.
To cheers he highlighted that people from across the United Kingdom were present, saying: "They are saying squarely to the leadership of the Labour Party "listen to us, hear us, give us a People's Vote".
"If Jeremy Corbyn were to come out and support a second referendum, and they had a snap election next month, I think they would win", said Claire Hallett, 60, who was with her dog Desmond, draped in an European Union flag.
A poll published over the weekend found 86 per cent of party members think there should be a vote on the outcome of Brexit negotiations.
Some sections of the crowd also chanted directly at party leader Jeremy Corbyn, saying: "Hey Jeremy, take a note, for the many, People's Vote".
"I think the time for vagueness is over", she said.
Tottenham MP David Lammy and peer Lord Adonis were among the speakers while MP Luciana Berger led the march.
"There is a lot of resentment, a lot of bitterness which I don't think will be very easily dispelled and there may be some Labour MPs who eventually leave on the basis of anti-Semitism issues", Fielding said.
It adds: "In these circumstances, the best outcome for the country is an immediate General Election that can sweep the Tories from power".
Brexit is one of several challenges facing Corbyn, who heads a divided party. He has strong support among grassroots members, many of whom have joined since he was elected leader in 2015.