An investigation into anti-Semitism by the Equality and Human Rights Commission has found Labour responsible for unlawful acts of harassment and discrimination.
The party could face legal action after the equalities watchdog found the party guilty of three breaches of the law, including political interference in the complaints process.
The EHRC inquiry was triggered in May 2019, when Jeremy Corbyn was leader, with the body saying it had been approached about a number of complaints.
Labour has been served with a legal notice and has six weeks to respond with an action plan.
The body did not make a finding on whether the party was institutionally anti-Semitic, but said its analysis “points to a culture within the party which, at best, did not do enough to prevent antisemitism and, at worst, could be seen to accept it”.
The report names two individuals whose anti-Semitic conduct the Labour Party was responsible for - former London mayor Ken Livingston and councillor Pam Bromley.
Both were found to have used anti-Semitic tropes and suggested anti-Semitism accusations were fake smears. The EHRC found they were representing the Labour Party at the time.
The EHRC also said it “uncovered serious failings” in the way complaints were handled, until at least 2018.
The report stated: “We found that the Labour Party’s response to anti-Semitism complaints has been inconsistent, poor and not transparent, in terms of the process used, reasons for decisions, record-keeping, delay and failures to communicate with complainants.
“Some complaints were unjustifiably not investigated at all.”
The body found the party is responsible for three breaches of the Equality Act (2010) relating to:
The report also found “evidence of political interference in the handling of anti-Semitism complaints throughout the period of the investigation”.
The EHRC examined 70 files and uncovered 23 instances of “inappropriate involvement” by people working in then leader Corbyn’s office.
The 130-page report on the investigation concluded there were “significant failings in the way the Labour Party has handled anti-Semitism complaints over the last four years”.
It said they found “specific examples of harassment, discrimination and political interference”, but also noted “a lack of leadership within the Labour Party on these issues”, which it said was “hard to reconcile with its stated commitment to a zero-tolerance approach to anti-Semitism”.
It said: “The Labour Party must live up to this commitment and acknowledge the impact that multiple investigations and years of failing to tackle anti-Semitism has had on Jewish people.”
Reacting to the report, the Jewish Labour Movement said blame for the “sordid, disgraceful chapter” in the party’s history “lies firmly with those who held positions of leadership”.
A statement from the group said: “Since 2015, we have consistently warned the Labour Party about a deepening casual culture of anti-Jewish racism, that saw Jewish Labour members and activists harassed and discriminated against.
“Instead of listening to our growing concerns over the scale of the challenge, we were told that this racism was imagined, fabricated for factional advantage or intended to silence debate.
“Today’s report confirms that our voices were marginalised and our members victimised.
“As set out in forensic detail by the EHRC, the blame for this sordid, disgraceful chapter in the Labour Party’s history lies firmly with those who held positions of leadership – those who possessed both power and influence to prevent the growth of anti-Jewish racism, but failed to act.”
Asked if the EHRC probe marked the most shameful moment in the party’s history, shadow health secretary Jonathan Ashworth agreed that “it probably was, yes”.
This article originally appeared on HuffPost UK and has been updated.