Jeremy Corbyn and his deputy Tom Watson have said they will back another EU referendum if party members call for one.
The Labour leader said he would "adhere to" any decision made at the party's annual conference today in Liverpool. But he told the Sunday Mirror he was not specifically calling for a new vote.
“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," he said.
Meanwhile, deputy leader Tom Watson wrote in the Observer that the views of party members must be respected.
A YouGov poll for the newspaper suggests 86 per cent of party members want a vote on the Brexit deal – a so-called People's Vote – but the leadership has previously said it would "respect" the result of the referendum in June 2016.
Labour has consistently said it would prefer the issue of Brexit to be resolved through a general election. The party has demanded that any Brexit deal brought home by Theresa May must meet six tests, including that the new deal offer the same benefits to the UK as current membership.
The prime minister was rounded on by EU leaders at a summit in Salzburg, Austria, who rejected her Chequers plan, saying it undermines the Single Market and amounts to "cherry-picking".
Their rejection prompted a retaliatory speech from May, who said the EU must treat the UK with more "respect" in Brexit negotiations. She said talks had reached an "impasse" and could only be resolved by the EU softening its stance on the issue of the Irish border.