Nine people who were suing the Labour party after they were named as complainants in a leaked report over antisemitism have dropped their case. The nine were suing Labour for failure to protect their data and invasion of privacy after they were identified as having made complaints about antisemitism in an 860-page document that claimed factional hostility towards Jeremy Corbyn contributed to the party’s ineffective handling of such complaints. The discontinuation of the case was revealed in documents lodged at the high court on Monday. It is unclear if an out of court settlement has been reached. In a linked case, Labour is suing five former staff that it accused of leaking the internal report. The cases had been expected to be heard together next year and were seen as having the potential to prove highly damaging to the party in the run-up to the next general election. The Guardian understands that the development does not affect the party’s claim against the former staffers, who include Corbyn’s former chief of staff Karie Murphy and his former director of communications Seumas Milne, although there is speculation it may prompt the party to reconsider. It was estimated Labour could face a legal bill of £3m to £4m from fighting the cases. The party has already spent more than £500,000 as part of its lawsuit against the five former staffers. The internal report, titled The work of the Labour party’s governance and legal unit in relation to antisemitism, 2014–2019, was compiled to be submitted – although it never was – to an investigation by the equalities watchdog into antisemitism allegations within Labour. It leaked days after Keir Starmer became party leader, and his supporters said this was done to “smear whistleblowers” who had exposed antisemitism. It included details of staffers’ private conversations expressing hostility towards Corbyn or his close allies and bemoaning Labour’s better than expected performance in the 2017 general election. In April, seven of the nine complainants were named in a high court order, including the Labour Against Antisemitism spokesperson, Euan Philipps, and its members Emma Picken and Denny Taylor. Two of the complainants were permitted to remain anonymous. The other staffers being sued by Labour are Georgie Robertson, Laura Murray and Harry Hayball. All denied leaking the report by Labour’s governance and legal unit, and an investigation by the Information Commissioner’s Office into three of them decided there was insufficient evidence to prosecute, raising questions over the strength of Labour’s case. Last month, Mr Justice Chamberlain ordered the party to pay £90,000 as an interim contribution towards Murphy’s costs. Other legal costs Labour has incurred so far include £99,108 towards the five employees’ application for the lawsuit against them to be struck out, and £103,626 towards an anonymity application by the claimants in the case whose names were revealed in the report. A Labour party spokesperson said: “We are grateful to have had the opportunity to have met with members of Labour Against Antisemitism to discuss their concerns and to thank them for all their work in challenging antisemitism. We are pleased to be able to move forward in a positive manner. The Labour party is committed to continuing its work on combating antisemitism.” • This article was amended on 13 September 2023. An earlier version stated that seven of the nine claimants against the Labour party “unsuccessfully sought anonymity in the legal proceedings”. In fact, all nine were granted anonymity earlier in the proceedings, but only two sought – and were granted – continued anonymity this year.