Keir Starmer has cut funding for Young Labour and scrapped its annual conference after the youth wing accused the leader of “backing Nato aggression” over the Ukraine crisis.
The dramatic clampdown is the latest clash between the leader and left-wing activists and comes after Young Labour's Twitter account was restricted "until further notice" by party chiefs today.
Posts said activists running the account for Young Labour, which is for members 26 and under, had been "actively detrimental to the party’s core objectives: to promote Labour candidates and policies, and to win elections".
It follows a series of bitter public rows, the latest of which saw the youth wing hit out at the defensive alliance Nato after Russia launched a brutal attack by land, sea and air in Ukraine - Labour's official policy is pro-Nato - and “offer solidarity with those organising against this, including members of Stop the War”.
A Labour source told the Mirror: “Young Labour is supposed to be a place for younger members to get away from factional rubbish.
"Unfortunately not every one seems to understand that. Labour will no longer tolerate the selfishness of those who aren’t focused on winning the next election.”
On Thursday, the leader threatened to remove the whip from 11 Labour MPs - including former Jeremy Corbyn frontbenchers Diane Abbott, Richard Burgon and John McDonnell - for supporting a Stop The War letter.
Independent MP and former leader Mr Corbyn, who lost the Labour whip more than a year ago, was among the signatories.
The statement questioned NATO's legitimacy and accused the defensive alliance of "eastward expansion".
It also claimed the UK Government of having "no proposals for a diplomatic solution to the crisis" and said "Britain needs to change its policy, and start working for peace, not confrontation".
All 11 MPs later withdrew their backing for the letter following contact with Labour's chief whip Sir Alan Campbell.
Young Labour later lashed out at Sir Keir and declared its support for Stop The War "and other pro-peace activists”.
The Mirror has contacted Young Labour's chair for comment.
Meanwhile, Momentum, which was set up initially to support Jeremy Corbyn's leadership hit out at the "silencing" of the Young Labour Twitter account.
A Momentum spokesman said: “We strongly condemn this shameful and anti-democratic attack on young members within Labour.
"This is a blatantly factional move designed to silence critics of Labour’s direction under Starmer, exploiting a moment of global crisis.
"It’s also a recipe for disaster, as Starmer is set to further alienate the younger voters who are a key pillar of Labour’s core support. Sadly, this Labour leadership appears so vindictive that it will willingly cut off its nose to spite its face.”
