Rather than committing the party to supporting a new referendum, the motion states that "if we can not get a general election, Labour must support all options remaining on the table, including campaigning for a public vote".
Speaking to the BBC's Andrew Marr as the party faithful gathered in Liverpool, Corbyn said he would be "bound by the democracy of our party" were members to vote in favour of a second referendum, although he added he would wait and see what wording would be put in front of the delegates after a meeting on Sunday evening. Most of the party's half a million members voted in 2016 to remain in the European Union, but many of its 257 lawmakers represent areas of the country that wanted to leave.
It came as senior Labour figures engaged in an extraordinary public squabble over whether the party should then call for a second referendum - and what should be on the ballot paper.
"No "ifs", no "buts", Starmer will say in a speech to the party's annual conference, according to advance extracts.
"What we need the Labour leader to do is to admit and apologise that many incidents of anti-Semitism within certain sections of the Labour party have not been dealt with properly".
He stressed the party was deliberately not being "prescriptive" about the question that could be posed in another referendum, and was "certainly not ruling out" the option to stay in the EU.
It is an argument Labour's leadership feels keenly, and one that nearly certainly chimes with Corbyn, a veteran eurosceptic who in 1975 voted "No" to Britain's membership of the then-European Community.
However, Labour's primary strategy appears to be forcing the government into an early general election, something the Brexit Secretary, Dominic Raab, categorially ruled out on Sunday.
Asked about marathon party talks on the issue, he said: 'We weren't ruling out options and no one was ruling out Remain'. May has a working majority of just 13 in the 650-seat parliament and a former junior minister said this month as many as 80 of her own lawmakers are prepared to vote against a Brexit deal based on her Chequers proposals.
But quizzed this afternoon on whether McDonnell was right, Starmer said: "The question of a public vote should be open".
But some Tory moderates had hoped that, faced with the prospect of no deal, some Labour MPs would vote with the Government.
'And if the Prime Minister thinks we'll wave through a vague deal asking us to jump blindfolded into the unknown she can think again. We will vote down a blind Brexit'.