Labour MPs savage Jeremy Corbyn over anti-Tom Watson briefing

Senior party sources said the majority of Mr Corbyn's top team had joined forces in "slapping down" Mr Watson over his public criticisms of Momentum.

That followed a secret recording of a speech made by Momentum boss - and close Corbyn ally - Jon Lansman in which he said Unite would affiliate to the group if Len McCluskey is re-elected its general secretary.

Mr Lansman also claimed an early election would "disrupt" Momentum's plans to take a more influential role in how the Labour party is run.

At a Shadow Cabinet away day at the headquarters of Unison, Mr Watson was rounded on by John McDonnell, Diane Abbott, Jon Trickett and Emily Thornberry. However, John Healey, Jon Ashworth, Angela Smith, Barbara Keeley and Keir Starmer all criticised Mr Lansman.

Mr Corbyn and Mr Watson put their names to a joint statement calling for party unity, but within minutes senior sources loyal to the party leadership issued a statement attacking the deputy leader.

"Jeremy was supported pretty much unanimously in Shadow Cabinet in slapping down Watson for what has been seen as a reckless intervention designed to influence Unite's general secretary election," they said.

At the PLP meeting, several MPs - including John Spellar, Wes Streeting and David Winnick - defended Mr Watson and blamed Mr Corbyn's aides for the briefing against him.

Mr Streeting said: "What more evidence do they need about Momentum? Every member of the Shadow Cabinet who failed to speak out should search their consciences as they drive the Labour party off a cliff."

PLP chairman John Cryer said Momentum were "a party within a party" and said the leaks from party sources "bore no relation to the actual meeting".

Ian Austin told Mr Corbyn to "look in a mirror" and added: "Having a mandate is one thing, actually being able to do the job is another."

In a thinly-veiled swipe at Mr Corbyn, Scottish Labour leader Kezia Dugdale, who also addressed the meeting, said: "Never forget the best way to represent and deliver for working people will always be from the government benches."

After the meeting, former Labour MP Lord Watts confronted Seumas Milne, Labour's head of communications and strategy, and told him he was "a disgrace". Mr Milne accused him of "abusing Labour party staff".

Speaking afterwards, a spokesman for Mr Corbyn described the PLP meeting as "robust", and denied the leader's office were behind the briefings against Tom Watson.

He said: "I've been giving no such briefings. You'll know as well as we do that after PLP meetings in particular and after other Labour party meetings there's often briefing that goes on and the message that Jeremy gave to the meeting is that we need to be a united party and we need to be talking about the issues that affect our voters.

"That's what we should be talking about, not the internal affairs of the Labour party. He'd encourage everybody who has been briefing about the internal affairs of the Labour party to follow that line."