JEWISH activists have warned that the official investigation into anti-semitism in the Labour Party is “defective” and violates human rights law.

The Equality and Human Rights Commission (EHRC) launched a probe into Labour after receiving complaints from the Jewish Labour Movement and the Campaign Against Anti-Semitism.

But now another group, Jewish Voice for Labour (JVL), has written to the watchdog to express concerns about the investigation.

JVL said the inquiry’s terms of reference were “defective and in breach of the statutory requirements imposed on the commission.”

This was because it had failed “manifestly” to specify the nature of the unlawful acts that it was investigating.

The group warned that this violated the Equality Act 2006, which sets out the commission’s powers.

It said: “In order to comply we submit that the commission must without delay repair these defects and publish the nature of the unlawful act or acts which the commission suspects.”

JVL also warned that the watchdog needed to take into account the “appropriate political context.”

“Our experience is that in the years since Jeremy Corbyn became leader of the Labour Party, many Jews have chosen to join or rejoin the Labour Party.

“This is, for example, illustrated by the testimonials from 143 Jewish members of the party which were submitted to the commission, expressing contentment with their membership of the party and in many cases indignation at suggestions that there is a particular problem with anti-semitism within the Labour Party.”

The group warned that the “heavy pressure” on Labour was “masking the documented growth of anti-semitism on the far right.”

JVL acknowledged that there had been problems with the party’s complaints system but blamed these on the last general secretary Iain McNicol, who was known to oppose Jeremy Corbyn.

“There were defects in the party’s handling of complaints, but these related to a broad range of issues, particularly in the period before the change of general secretary,” the group said.

Shortly before Jennie Formby took over the role in April 2018, JVL said “there seems to have been a concerted effort by some staff to make her job difficult” by destroying files and leaking confidential information to the media.

An EHRC spokeswoman said: “We are carrying out our investigation in accordance with the terms of reference set out on our website.

“We will review all the evidence we have received.”