Labour shadow minister Chuka Umunna has said there is “tension” between the Labour party membership and the parliamentary party under the leadership of Jeremy Corbyn.
Speaking on ITV's The Agenda, he acknowledged that Mr Corbyn has enthused many party members.
However, he said the party's MPs - some of whom are markedly more centrist than their leader - represent a much larger section of the electorate.
If you look at the research on things like Trident, the parliamentary party would be closer to the views of the voters than the members and there's that tension.
Mr Umunna, who previously stood for the party leadership, also refused to rule out running again.
"I would said I would never say never," he said, while adding that at the moment the question did not arise as there is no vacancy.
Watch in full on The Agenda on ITV at 10.40pm tonight.
At least one Labour MP has publicly criticised party leader Jeremy Corbyn's appearance at an anti-nuclear march in London today.
Michael Dugher, MP for Barnsley East who was sacked from the shadow cabinet last month for "too much straight talking," has taken to social media to voice his disapproval.
Writing on Twitter this afternoon, Mr Dugher likened Mr Corbyn's appearance at the anti-Trident rally to Christmas coming early for the Conservative party.
Mr Dugher previously described Mr Corbyn's plans to scrap Britain's Trident nuclear deterrent as "barmy."
Jeremy Corbyn has warned that the UK’s Trident nuclear defence could only lead to “mass destruction” as he joined thousands of people at an anti-nuclear march in London.
Organisers estimated that "many tens of thousands" of people had braved cold weather to join the protest, which is the biggest of its kind for a generation.
They hope it will deter the government from renewing the nuclear weapons system.
The Labour leader’s appearance could widen a split with some members of his own party who have refused to back his insistence that Trident should be scrapped.
He told marchers today that you “don't achieve peace by planning for war”.
If a nuclear war took place there would be mass destruction on both sides of the conflict.
Everyone should think about the humanitarian effects on people across this globe if they're ever used.
The Ministry of Defence has estimated acquiring four new submarines to carry the Trident deterrent will cost £31 billion over 20-year procurement programme.
Mr Corbyn favours unilateral disarmament but some of his shadow cabinet - including shadow foreign secretary Hilary Benn - disagree with him.
Britain's Trident nuclear deterrent allows it to play an "outsized role on the global stage", the US defence secretary has said.
Ash Carter said the nuclear-armed submarines are an "important part of the deterrent structure of Nato".
MPs are expected to vote on plans to renew the weapons system, with Labour split over its policy on the issue. Jeremy Corbyn favours unilateral disarmament but faces a showdown with some of his shadow cabinet.
Mr Carter told the BBC that Trident enables Britain to "continue to play that outsized role on the global stage that it does because of its moral standing and its historical standing".
"It's important that the military power matches that standing and so we're very supportive of it," he added.
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