Labour deputy leader Tom Watson has asked to be copied in to all complaints about antisemitism and bullying in a clear challenge to general secretary Jennie Formby’s highly criticised effort to get to grips with the problem.

In an email sent to party MPs and Peers on Monday, Mr Watson wrote: “Over recent weeks a number of colleagues have shared their frustration that incidents of antisemitic, racist abuse and bullying have not been dealt with in an adequate and timely manner or that colleagues have not been informed of the outcome of party investigations.

“In response to these concerns I have requested that the general secretary improve procedures by appointing a named member of staff that could be a point of contact for colleagues to raise cases and be updated on progress.”

Mr Watson then added: “As your deputy leader I am deeply ashamed of abuse that colleagues are receiving from within the party.

“In order to properly access and monitor the scale of the problem I would like to see any issue or complaint you raise with the general secretary.”

During an appearance on the BBC’s Andrew Marr show on Sunday, Mr Watson revealed he had submitted a dossier of 50 complains over antisemitism made by Labour members to Jeremy Corbyn.

Details of the dossier, seen by the Guardian, include Labour members sending tweets linking Hitler and the Rothschilds, accusing Jews of murdering children and questioning whether Jewish MPs and councillors have “human blood”.

All of the cases have been raised by Mr Watson or other Labour MPs over a period of several months, but no action has been reported back to those who have raised the complaints, he said.

One case involved a tweet which read: “Wonder why Jewish people are hated wherever they’ve settled over last 2,000 years. Their double dealing, back stabbing, cheating chilling.”

Another concerned a tweet saying that “Jews murder people and children”.

Mr Watson told Mr Marr: "This week I've had 50 complaints of antisemitism from my parliamentary colleagues that I've shared with Jeremy and, for us to address that now, I think he needs to take a personal lead on examining those cases and, if necessary, recommending to our NEC what has to be done."

He added: "I'm saying for us to hold this party together, things have got to change.

“There's almost a sort of crisis for the soul of the Labour Party now and that means that everyone that cares about our future, whatever tradition they represent, has to find it within themselves to work more closely together."

Appearing on Radio 4’s Today programme on Monday, Jon Lansman, the founder of the Momentum organisation, admitted the party had a “much larger” problem with “hardcore antisemitic opinions”. He said he was “extremely upset” by Luciana Berger’s departure from the party last Monday but rejected her claim that the party is “institutionally antisemitic”, adding: “I think any Jewish member of the party leaving the party because of antisemitism is a source of tremendous regret and sadness and some shame.”