THE Labour Party has "reached a clear view" about who leaked an internal report into allegations of anti-Semitism, lawyers representing a former senior staffer have told the High Court.

An 860-page report on Labour’s governance and legal unit, which found “no evidence” of anti-Semitism being handled differently from other complaints, was leaked in April last year.

The internal investigation carried out in the final months of Jeremy Corbyn’s leadership concluded that “factional opposition” towards the former leader contributed to “a litany of mistakes” hindering efforts to tackle the crisis.

The leaking of the dossier, which included emails and WhatsApp messages between several senior Labour officials, prompted new party leader Sir Keir Starmer to launch an inquiry.

Emilie Oldknow – Labour’s former director of governance, who is also married to shadow health secretary Jonathan Ashworth – wants to bring claims for defamation and misuse of private information over the leaking of the report, which contains more than 500 references to her.

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At a remote hearing on Monday, her lawyers asked the High Court to grant an order requiring Labour to reveal who leaked the report so she can sue them.

William Bennett QC, representing Oldknow, told the court that the report was a “politically-motivated hatchet job” which sought to blame Oldknow and others for Labour’s “failure” to deal with allegations of anti-Semitism.

The report also accused Oldknow and her colleagues of “undermining Jeremy Corbyn’s leadership”, Bennett said.

He said the party decided the report “could not be submitted to the Equality and Human Rights Commission because it was deliberately misleading and relied on improperly obtained private correspondence”.

However, last April, “a faction within the Labour Party published the report to the media”, Bennett said.

He told the court Oldknow “wishes to bring those people to account, who anonymously, surreptitiously leaked the Labour Party report against the wishes of the Labour Party”.

Bennett said in written submissions that Labour has “reached a clear view as to who was responsible for the leak”, but has “studiously avoided giving any explanation as to what happened”.

He said Oldknow has “a strong case” to bring claims for defamation and misuse of private information against those who leaked the report.

But she “needs to know which wrongdoer played what role and whether there is a viable case against some or all of them”, Bennett said.

Anya Proops QC, representing the Labour Party, said the leaked report, which “contained extensive quantities of personal data relating to a wide number of individuals, including Ms Oldknow”, was “highly confidential”.

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She said in written submissions that Labour’s investigation into the leak is “now at an end” and that the party has concluded that “it did not authorise the leak and it is innocent of any responsibility”.

Proops said Labour understood that Oldknow’s application was “a necessary step” for her to be able to “vindicate her rights” following the leak.

She told the court: “We are entirely content to disclose to Oldknow effectively the underlying information enabling her to identify the persons responsible for the leak.”

But Proops said Labour did not want to “provide our subjective opinion on who is legally liable” for the leak.

She asked for the application to be adjourned, to ensure that “adequate protection is given to those third-party individuals who would be most seriously affected” if Oldknow’s application was granted.

Five anonymous individuals who deny any responsibility for the leak were also represented at the hearing.

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Their barrister Jacob Dean said in written submissions: “They have cooperated fully with the various investigations into that leak, providing detailed personal, private and confidential information to those investigations, on assurances of confidentiality.”

Dean argued that “the potential for injustice is manifest” if Labour was forced to “disclose a mass of evidence … from which the [party] has drawn certain conclusions in order to allow the applicant to draw her own, possibly different, conclusions”.

He also said: “It is apparent that the [party] does not know who leaked the report.”

Dean said Labour’s statement that it has “reached a clear view” as to who was responsible suggested that the party “does not have any direct or admissible evidence”.

The barrister also told the court that the trade union Unite was “supporting” the five individuals in their case and would “satisfy any costs order against them”.

At the conclusion of the hearing, Mrs Justice Tipples ruled that the five individuals could not participate in the hearing and said she would give her ruling on Oldknow’s application on Tuesday.