More than 30 whistleblowers including current members of staff will submit evidence to the equalities watchdog???s examination of Labour antisemitism, amid warnings that the party had failed to grasp the seriousness of the investigation.
The revelation comes after eight former members of staff went public in a BBC Panorama programme alleging consistent interference in the disputes process by senior Labour aides.
Labour has complained about the programme to the highest level of the BBC, claiming the staff members were disaffected and motivated by political opposition to Jeremy Corbyn.
But some members of Labour???s governing national executive committee (NEC) fear the party is not doing enough to prepare for a pending investigation by the Equality and Human Rights Commission (EHRC), while senior MPs have also called for a more transparent approach.
Some members of the NEC raised serious concerns at a meeting on Tuesday that party chiefs had not shared the submission to the EHRC investigation with them, making it impossible for them to respond credibly to the watchdog???s eventual findings.
One source close to the committee said: ???The party has not grasped the consequences of how serious this investigation is if Labour is found guilty. There is no concept of the extremely severe ramifications of that decision.
???This is an extremely serious thing, we are effectively the trustees of the party, and we are being left entirely in the dark about how we respond to this.???
The EHRC does not have the power to fine or prosecute individuals but it could create a legally enforceable action plan for organisations and make recommendations if it finds against Labour.
The Jewish Labour Movement (JLM) said it had detailed witness statements from 30 former and current Labour members of staff that it was planning to submit to the EHRC.
Several more whistleblowers are understood to have approached the group since the programme was aired on Wednesday night.
A JLM spokesman said: ???The testimonies of whistleblowers confirm what we have suspected for some time. The culture and scale of antisemitism within the party has been perpetuated and exacerbated by those at the very top. Those responsible must be held accountable.???
Labour???s deputy leader, Tom Watson, said he, the shadow cabinet and the NEC had been denied access to information on the scale of the problem and the party???s official response to the investigation by the equalities watchdog.
In an extraordinary broadside against Labour???s general secretary, Watson wrote to Jennie Formby on Thursday expressing outrage at the way former staff members had been treated and said the party must release its submission to the EHRC.
???Only sunlight can disinfect Labour of antisemitism now,??? he wrote. ???I believe there is no express legal basis for withholding the document from the chair of the NEC or from me as deputy leader.
???The submission here is no minor matter that can simply be left to others. As I have said before, I have not delegated my responsibilities in this to you. Nor could I do so. The shadow cabinet and NEC need to know what you have sent to the EHRC in our party???s name, and we need to know urgently.
???Every member of these two bodies is bound by a moral and political responsibility to eradicate antisemitism from the party and restore our standing with the Jewish community.???
Keir Starmer, a shadow cabinet member, said the party should show it was ready to ???throw open the books and say you have got access to anything???.
Watson also said he was concerned by emails revealed by Panorama, which appeared to suggest Formby had deleted messages and also used an external email account at the Unite trade union for private communications. Watson released an email from Formby in which she assured him she was preserving all emails for the EHRC to examine.
A Labour source said Formby had offered to meet Watson to provide him with the party???s response to the EHRC. ???This week Jennie Formby took time out of her chemotherapy treatment to update the shadow cabinet on this. Tom Watson was present but did not ask any questions on this,??? the source said.
The Labour source also said Formby had written to Watson in March asking him not to personally criticise Labour staff. Claudia Webbe, a member of the NEC and the chair of Labour???s disputes committee, hit back at Watson, saying Formby should not be targeted while undergoing chemotherapy and suggested he should resign.
She said Watson had ???engaged in public attacks on the Labour party???s general secretary despite your clear knowledge she is receiving chemotherapy treatment for cancer. This is not behaviour befitting of the office of deputy leader. You should consider your position.???
JLM said it had begun collecting statements since September 2018 to refer to the EHRC. The group, which is the party???s oldest and only official Jewish affiliate, said it wanted to pay tribute to those who had come forward, particularly four who had already broken non-disclosure agreements.
???In the face of legal action, they have demonstrated bravery and integrity in abundance. We???d urge any party officer or staffer, past or present, to come forward now and tell us and the EHRC what you know,??? the spokesman said.
One source suggested the Panorama documentary contained ???around 5%??? of the detail that had been collated to submit to the EHRC.
The EHRC launched a formal investigation into whether Labour ???unlawfully discriminated against, harassed or victimised people??? from the Jewish community in May, saying it had received a number of complaints about Labour???s handling of allegations.
The party has said it will cooperate fully with the investigation but rejected any suggestion that it did not handle complaints ???fairly and robustly, or that the party has acted unlawfully???.
A number of other former and current members of staff are expected to approach the EHRC directly, rather than through JLM???s formal submission. Others may be compelled to come forward.
A senior NEC source said they believed evidence given by those who were called by the EHRC could be the most damaging.
???The documentary will prompt many more people to come forward, or to speak freely if they are compelled to give evidence to the EHRC,??? the source said. ???It hit home when the whistleblowers said how when you try to do something about injustice but can???t, you start to feel complicit.???
NEC members intend to raise the matter again at the meeting of the equalities committee next week and again at a full meeting the following week.
A Labour spokesman said: ???Our records show that after Jennie Formby became general secretary, the rate at which antisemitism cases have been dealt with increased more than fourfold.
???Complaints about antisemitism relate to a small minority of our members. We have robust procedures for dealing with such complaints, which we are continuing to improve and we are cooperating fully with the EHRC.???