A member of Labour’s senior disciplinary body, the national constitutional committee, has accused Jeremy Corbyn’s office of intervening in the disciplinary cases of Ken Livingstone, Dame Margaret Hodge and Marc Wadsworth.

Peter Mason also said the party had received thousands of complaints of antisemitism, which would take months, if not years, to resolve – and claimed “disgraceful” cases were not dealt with if they were not reported in the national media.

Mr Mason, an Ealing councillor, spoke at the Jewish Labour Movement conference.

In a leaked recording of the discussion, reported in the Sunday Times, Mr Mason said: “We’re just having to take decisions on… nasty people who just behave in intolerable ways to each other.”

Labour said claims of Mr Corbyn’s interference were “misinformation” and that dealing with cases had been speeded up.

Meanwhile, Trevor Phillips, former chairman of the Equality and Human Rights Commission, has launched a scathing attack on Labour and Mr Corbyn over antisemitism.

During a debate on ways to heal divisions in Britain, hosted by the Policy Exchange think-tank, Mr Phillips said: “It doesn't help that one of our great parties, the one I belong to, is led by antisemites and racists who basically want to eliminate anyone who disagrees with them.”

Asked subsequently by the Mail on Sunday if he included the Labour leader in his “antisemites” attack, he replied: “Yes – I think Jeremy Corbyn's views have been pretty well ventilated and exposed.”

Mr Phillips said that if Jeremy Corbyn “were to step down tomorrow or be hit by a bus, don't forget there are people around him who are important in the party who supported him…

“There are literally tens of thousands of activists who defend the behaviour that we have all been seeing from the leadership.”

Dismissing Mr Phillips’ claims, a Labour spokesman said: “Jeremy Corbyn and the party leadership are life-long anti-racists who are determined to tackle antisemitism both within the Labour party and in wider society.”

It has also been reported that Ewa Jasiewicz, the British anti-Israel activist who spray painted graffiti “tainted with antisemitism” on a Warsaw ghetto wall, will speak at a Momentum event taking place in parallel with the Labour Party conference. She will address Momentum’s politics and arts festival, where speakers are also due to include Jeremy Corbyn and John McDonnell.

Interviewed on Sky News, Labour MP Chaka Umunna called his party "institutionally racist", adding: "The failure to deal with the racism that is antisemitism is particular and clearly is a problem."