Jon Lansman, the architect of Jeremy Corbyn’s rise to power, thinks the “very existence” of pro-Corbyn Jewish Voice For Labour group is inflaming tensions between Labour and the Jewish community, sources have said.

A senior figure in left-wing campaign group Momentum said that its founder, Jon Lansman, believed it is problematic that senior JVL figures claim to speak for the entire community but actually only reflect the views of a small faction of anti-Zionist Jews.

The source also told the JC that Mr Lansman felt it was entirely wrong for leading JVL figures to suggest that their organisation deserves equal recognition from Labour, on a par with the bigger, more established Jewish Labour Movement.

JLM has criticised the party leadership’s handling of the antisemitism crisis, while JVL has sought to play it down.

The Momentum chief is also said to have taken a dim view of John McDonnell’s decision to attend an event last week with JVL co-chair Jenny Manson, which was meant to promote her bid to stand as a Labour candidate in Finchley and Golders Green.

But the source said Mr Lansman believed the Labour shadow chancellor has played a productive role overall in trying to end the party’s antisemitism crisis.

The source told the JC: “It’s not just in terms of the membership numbers against groups such as the Jewish Labour Movement that the JVL’s claim for equal treatment does not stack up as far as Jon is concerned.

“He believes that JVL speaks for a very, very small part of the Jewish community.

“It may speak for a bigger number of Jews with Labour itself, but this doesn’t help relations with the wider Jewish community, which has a broader view.

“Jon actually believes the real problem with JVL is their very existence.”

At the heart of Mr Lansman’s issue with JVL was their opposition to the state of Israel, the source added.

“Jon believes everyone is entitled to their view on Jewish politics, especially when the arguments are being made from Jews themselves,” they said. “But there needs to be an acceptance of Israel’s right to exist, alongside a Palestinian state…

“It is possible to argue about the Occupation of the West Bank, or about Gaza. But to actually argue about Zionism itself is only going to exacerbate the problem.”

The source refused to comment on claims Mr Lansman had fought to stop JVL activist Stephen Marks from appearing on a left-wing “slate” of names agreed on Wednesday to be recommended to Labour members for election onto the party’s disciplinary body, the national constitutional committee (NCC), next month.

The source also dismissed reports on a pro-Corbyn news blog that Mr Lansman had described Jewish Labour MP Luciana Berger as “pliable” to two activists from her local party who were longing to deselect her.

According to the source, Mr Lansman had suggested the activists attempt to fix deteriorating relations with their MP who had served Mr Corbyn well as a shadow minister in the past. 

Meanwhile, Mr McDonnell has claimed Labour had now dealt with “virtually all” antisemitism cases from party members that were unresolved in July.

The shadow chancellor also claimed the party’s eventual decision to adopt the full IHRA definition of antisemitism – after a protracted standoff with the Jewish community over the summer - was one of the “key strategic tests for me.”

Mr McDonnell told a Westminster lunch on Wednesday: “On the cases that were outstanding in July, I'm told that virtually all those cases have been dealt with.

“So all those historic cases have been dealt with.

“Others have come in since then so we've now got a system that's dealing with those effectively and I'm pleased about that. We've dealt with the issue of the IHRA definition and examples and we've adopted that and that was one of the key strategic tests for me. We're now into the stage where there will be further discussions and consultations.”

Asked about continued antisemitism within the party and elsewhere in the world, he said: “My view is it's a present threat for everybody in society and we've got to be constantly vigilant. I think the atmosphere in the Labour Party at the moment is to be constantly vigilant and to tackle it wherever it arises.”