Mr Corbyn is facing one of the most dangerous periods of his leadership after he was last week forced to suspend Naz Shah, a Labour MP, and Ken Livingstone, the former Mayor of London, over alleged anti-Semitic comments.

Jonathan Arkush, the President of the Board of Deputies of British Jews, said that Mr Corbyn's failure to accept that there was a more widespread problem is "an issue in itself".

He said: "Labour will need to consider whether the compliance unit is the right approach or whether there needs to be a stronger mechanism to deal with what we see, to our sadness, to be a pretty serious problem in the current party membership."

John Woodcock, a Labour MP and critic of Mr Corbyn, said: "The Labour party should make public the number of incidents it has had reported in recent years to the present, we mustn't allow any impression that we are seeking to minimise this very serious issue or sweep it under the carpet."

Mr McDonnell has previously called for the compliance unit to be scrapped altogether. His intervention was described as "sickeningly irresponsible".