Video report by ITV News Political Correspondent Libby Weiner
Labour's Brexit stance appears ever more confused at the party conference in Brighton, despite the event being seen as an opportunity to unify divided MPs.
Several members of Labour's top team, including deputy leader Tom Watson - who survived an attempt to remove his role within the party - have spoken out in support of remaining in the EU.
"We are a Remain party. We are a European party. We are an internationalist party. That is who we are. Not perfect, not pure. But overwhelmingly committed to Britain remaining in EU," he said at fringe event.
And Labour's London Mayor Sadiq Khan went a step further than Mr Watson, saying the party should whip all its MPs "to back that position".
And he told ITV News: "What I'm saying to Labour delegates is 'don't vote for a delay, don't vote for a fudge, vote for us to be a Remain party so we can make it unequivocally clear when it comes to a public vote after the general election we will campaign to Remain in the EU."
He added: "This is the most important issue for a generation, Brexit - the idea of staying neutral is ridiculous."
But speaking on BBC's Andrew Marr Show Mr Corbyn said Labour's Brexit position in a referendum depends on what kind of renegotiation Labour can achieve with the EU after a general election and “we don’t know if we’re going to get it yet”.
And Labour's members of Labour's National Executive Committee agreed with Mr Corbyn on the need to define a Brexit position after an election.
The NEC voted by 16 to 10 in favour of a statement setting out the plan which will see a Labour government strike a new deal with Brussels and then put it to a public vote, against remaining in the EU while pushing for reform.
A decision on how Labour would campaign in that referendum would not be taken until a special conference.
But while Labour's leader's office says the policy has been approved, NEC members have told ITV News Political Editor Robert Peston that they haven’t approved it and are requesting a new meeting.
When the suggestion was put to Mr Watson that he is deliberately defying the leader, he said: "I'm not defying anyone, I'm trying to put my honestly held views based on reflections I've heard from Labour Party members."
While remain backing MPs are unified on their position, Mr Corbyn is causing confusion by refusing to say which way he'd campaign in a general election.
Shadow home secretary Diane Abbott tried to explain Mr Corbyn's ambiguous Brexit position, saying "he is the leader of a national party" and has to consider everyone who voted to leave.
She told ITV News: "I am a Remainer, I represent a solidly remain constituency and I will be campaigning for remain.
"But Jeremy is the leader of a national party and he has to bare in mind that there are 17 million people that voted for Leave, some of them Labour supporters.
There had been a suggestion Mr Corbyn would remain neutral in a referendum held after a general election, but that position won't be maintained by Mr Corbyn's top circle.
Earlier in the day Mr Watson told ITV News "I think it’s very important we have a very clear message... and I’m pretty consistent in saying it should be delegates who decide what that is. I hope that we can give the country a very clear message."
Shadow foreign secretary Emily Thornberry agreed, telling ITV News the party policy on Brexit should be decided at the conference but added "I've made perfectly clear what I think".
When asked if she's worried about activists challenging her in the same way they challenged Mr Watson, she said: "Everything's fine."
Their comments come ahead of compositing Sunday evening, when members will do battle over what Labour's official Brexit policy should be.
Shadow Brexit secretary Sir Keir Starmer and Ms Thornberry are other members of Mr Corbyn's top team who want to remain within the EU.
The pair joined pro-EU protesters in chanting for a People's Vote "now" on the first day of the conference,
Scottish and Welsh Labour leaders have also declared they would also back remain in a new referendum.
The Welsh First Minister vowed to "wholeheartedly, vigorously and unapologetically" campaign for the UK to remain in the EU during a second referendum.
Mark Drakeford, leader of Welsh Labour, set out his stall after claiming up to 50,000 jobs could be lost in the country by a "crash-out Brexit".
And Scottish Labour leader Richard Leonard praised Mr Corbyn's leadership but said he would support the party taking a remain stance as Brexit talks rumble on.
Speaking on the BBC's Sunday Politics Scotland programme, Mr Leonard said: "I do think the time has come for clarity on this question and the Scottish Labour party, the Welsh Labour party take a similar view that we should be more overtly remain."