Labour left-wingers could use their new majority on the party’s governing body to take control of the influential disputes panel responsible for handling allegations of antisemitism against members.
Party insiders say the Momentum-backed members of Labour’s National Executive Committee (NEC) are likely to move to replace Ann Black, the long-standing chair of the panel.
The move would leave the far-left in control of a committee which plays a key role on disciplinary issues and which previously prided itself on being non-political.
Jeremy Corbyn's leadership of Labour has been littered with allegations of antisemitism from within the party.
Outspoken anti-Zionist Labour supporters including Jackie Walker, Tony Greenstein and Marc Wadsworth have all been suspended from the party after their cases were brought before the party's Disputes Panel.
One NEC source told The Independent: “It’s unprecedented for the left to put up a candidate against an experienced chair of the Disputes Panel, which is supposed to be a neutral body. They’re politicising it in a way that will take us backwards in terms of party unity and people having faith in the NEC to rule fairly on cases.
“At a time when we’re dealing with big issues such as antisemitism and sexual harassment, it’s worrying that the left is trying to remove an experienced chair who is seen as really neutral and is respected by both sides.”
Ms Black has been in the role for a number of years and although she backed Jeremy Corbyn’s leadership, she is viewed as not being left-wing enough for some in the Momentum faction.
Jeremy Corbyn has faced criticism from some left-wingers over suspensions from the party and the way disciplinary hearings, including one relating to former London Mayor Ken Livingstone, have been conducted.
One senior Labour source told the JC of their concern that “very little progress” had been made into the disciplinary hearing into former Mayor of London Mr Livingstone over his claim that Hitler was a Zionist.
Traditionally the disputes panel operates in a quasi-judicial way, conducting independent hearings and interviews on disciplinary issues.
The chair is typically appointed by consensus in a deal between the different political factions on the NEC.
Three Momentum backed candidates including Jon Lansman, founder of the group, were elected to Labour's NEC on Monday.