Senior Labour figures have clashed over whether there should be a second referendum on Britain's membership of the European Union.
Deputy leader Tom Watson was seemingly at odds with shadow home secretary Diane Abbott on the need for a second poll.
Speaking on BBC Radio 5 Live's Pienaar's Politics Mr Watson said "you shouldn't rule anything out" when engaged in "complex negotiations".
His comments came after shadow home secretary Diane Abbott told BBC One's The Andrew Marr Show that "the Labour Party doesn't support a second referendum".
Mr Watson said: "We've not said we want a second referendum, what we actually want is a negotiated settlement.
"The point about the vote this week was we don't want power to be taken away from unelected bureaucrats in Brussels, as the debate went in the referendum, to be given to the executive or unelected bureaucrats in Whitehall. We want Parliament to have a say on it."
When pushed on whether Labour would rule out a second referendum he said: "When you're in complex negotiations on behalf of the nation you shouldn't rule anything out.
"What I am trying to say to you, I don't think it is likely at all, it would be more likely that we try and renegotiate the deal should Parliament reject it."
Shadow international trade secretary Barry Gardiner said that Labour would "honour the referendum result".
He said: "The Labour Party has not said that we will have a second referendum. We will honour the referendum result, but we last week got a final vote for Parliament on the deal.
"That is the democratic guarantee that now is there because of Labour Members of Parliament and 11 Conservatives joining with us."
Mr Gardiner said after Brexit the UK had to remain "closely aligned with our major trading partner" - the EU - which could mean continued membership of the single market.
He told Sky News' Sunday with Niall Paterson: "We haven't swept either the single market or a customs union off the table. We have said we are not fixated on the structures, what we want are the benefits."
Shadow justice secretary Richard Burgon said: "Labour isn't calling for a second referendum."
He told BBC's Sunday Politics: "It could be the case that Theresa May caves in and starts to ask for another referendum, I very much doubt she will do that. We are not in government, many of these things are hypotheticals.
"But I can say very clearly: we are not arguing for a second referendum."