Labour leader Jeremy Corbyn is meeting senior aides at Westminster amid speculation he is gearing up for a reshuffle of his top team to "purge" key figures who disagree with him on issues like Trident renewal and bombing Islamic State (IS).
The Labour leader is expected to hold "preliminary" discussions with some of his shadow cabinet before potentially finalising a new line-up before it is due to meet on Tuesday lunchtime.
Shadow foreign secretary Hilary Benn's position is thought to be under threat after he made an impassioned Commons speech backing the extension of UK air strikes to Syria, while shadow defence secretary Maria Eagle's support for renewing the nuclear deterrent has also infuriated those close to Mr Corbyn.
Former London mayor Ken Livingstone - a close Corbyn ally - said he believed it might be "better" for Mr Benn to be moved to another post and thought it "quite likely" he could be asked to swap jobs with shadow home secretary Andy Burnham, though he insisted he did not know whether this was what the leader was planning.
However, shadow international development secretary Diane Abbott denied she was being lined up to replace Mr Benn, branding the rumours "poppycock and piffle".
Staunch Corbyn supporter Clive Lewis also said he did not want to succeed Ms Eagle, although he stopped short of ruling it out altogether.
The reshuffle process could be complicated as the Commons is not yet back from its Christmas break, and a number of frontbenchers are still in their constituencies.
Some believe the scope of the changes will end up narrower than mooted, as the leadership would face a major backlash in the parliamentary party if moderates were frozen out.
Mr Corbyn and his aides have gathered at his suite of offices on the parliamentary estate as they consider changes.
The Labour leader personally asked a group of reporters waiting outside to leave. He said: "Excuse me guys, do you mind not hanging around outside my office door? Could you all leave, please?"
Shadow cabinet minister Michael Dugher, whose own place is reported to be in jeopardy, has warned Mr Corbyn would end up with a "politburo of seven" at the top of the party if he attempted to surround himself with allies from the Labour left.
Shadow Europe minister Pat McFadden pointed out the Syria decision was a free vote among Labour MPs, arguing that Mr Benn should not pay the price for his views - particularly given Mr Corbyn's own long history of rebellion.
Mr Livingstone denied the party was in "civil war", but said it might be better for Mr Corbyn to move Mr Benn to a different job.
Mr Livingstone, who is co-chairing a review of Labour's defence policy with Maria Eagle, said he "got on fine" with the shadow defence secretary and it was "a matter for Jeremy Corbyn" if she remained in the post.
"I think what Jeremy has to do is putting together the team in the way he wants it and then refocus this debate about the economy," the former mayor told BBC Radio 4's World At One.
"It's not civil war. Jeremy Corbyn has seen his support go up amongst the party membership. He has got a commanding majority of Labour's National Executive Committee and - contrary to all the predictions - a majority of the shadow cabinet voted with him on Syria."
Mr Livingstone added: "There is a problem if - as we had with the debate on Syria - our principal spokesman stands up at the end of the debate and puts a completely different line to the leader of the Labour Party.
"Allowing genuine debate is one thing, but all we had was days of press coverage about splits between Jeremy Corbyn and Hilary Benn. I think that's counter-productive.
"It might well be the case - and I have no knowledge of this - that it would be better to move Hilary Benn to something where he is in agreement with Jeremy Corbyn rather than where he is in disagreement."
Speaking on BBC London's Vanessa Feltz show, Ms Abbott described speculation she could replace Mr Benn as "completely untrue".
"I've never been offered the job of (shadow) foreign secretary," she said. "There was never any question of me being offered it, or of it being debated. It's just, as they say, poppycock and piffle."
Shadow energy minister Mr Lewis told the BBC's Victoria Derbyshire programme it was Mr Corbyn's "prerogative as leader to be able to manage and shape the shadow cabinet" without it being seen as revenge.
He said that as a new MP elected only last year, he would only accept a major job such as shadow defence secretary if Mr Corbyn said it was "essential".
Mr Corbyn refused to comment on the reshuffle rumours when he was asked by reporters at a rail fares protest at King's Cross station earlier.