The Jewish Labour Movement has “downed tools” in the election campaign and declined to back the party it has supported for almost a century, because of Jeremy Corbyn’s refusal to stamp out antisemitism, the organisation’s chairman says.

With days to go before Thursday’s general election, Mike Katz, JLM’s chairman, says its members concluded “a while ago that Jeremy Corbyn is not fit to be prime minister” because his party was “failing its Jewish members and tolerating antisemitism”. Writing for the Observer, Katz adds: “The Jewish Labour Movement – a founding affiliate of the party, nearly a century ago – has for the first time effectively downed tools for the election, campaigning only for exceptional candidates who have been the best of allies to us in our fight against the party’s anti- Jewish racism.”

Why we in the Jewish Labour Movement have not campaigned for Jeremy Corbyn Read more

He says he and others have told Corbyn and his team until they are “blue in the face” of the problems and strength of feeling among British Jews, but have been met with “obfuscation, denial and delay”.

Scores of serving and former Labour officials have given sworn statements about antisemitism in the party as part of evidence submitted to the Equality and Human Rights Commission, which is investigating the issue. In May this year, the commission announced an inquiry under section 20 of the Equality Act 2006, having carried out preliminary investigations.

Last week, final submissions from the JLM to the inquiry were leaked to the media, including 70 sworn testimonies from current and ex-party staffers. These include detailed allegations of antisemitic abuse at party meetings and by members online.

The submissions also allege political interference in the disciplinary process by Jeremy Corbyn’s office, despite Labour’s insistence that the leadership has not got involved.

In particular, they claim that the supposed separation between the leader’s office and the party’s complaints unit broke down in August 2018 and that a staffer was instructed via WhatsApp to upload complaints on to USB sticks for the leader’s office to examine and make recommendations for future action.

In his article, Katz says: “The witness statements from members show that the all-pervading culture of antisemitism is present in all parts of the party; local party meetings, party conferences, online forums, the disciplinary processes and its officials.”

On Tuesday, Corbyn apologised for antisemitic incidents that involved Labour members and said he was dealing with the issue. “Obviously, I’m very sorry for what has happened,” he said after being asked to apologise in an interview on ITV’s This Morning programme.