The Labour Party has ended a formal accuracy complaint against six national newspapers after claiming the review process at the UK’s largest press regulator was “unacceptably compromised” by an email leak.

The party lodged a complaint with the Independent Press Standards Organisation in August over coverage of leader Jeremy Corbyn’s attendance at a wreath-laying ceremony in Tunisia in 2014.

Photos of Corbyn at the ceremony resurfaced in the Daily Mail on 11 August, with the newspaper writing: “A memorial wreath in his hand, Jeremy Corbyn stands feet from the graves of terror leaders linked to the Munich Massacre.”

The Daily Mail said Corbyn was pictured in front of a plaque beside the graves of members of Black September, the terror group that killed 11 Israeli athletes at the 1972 Olympics. The coverage was subsequently followed up in a number of other major newspapers.

Labour maintains that Corbyn had visited the Palestinian National Cemetery in Tunisia to join an annual ceremony honouring the victims of a 1985 illegal Israeli airstrike.

The complaint was made under Clause 1 (accuracy) of the Editors’ Code of Practice against the Times, the Sun, the Daily Mail, Daily Telegraph, Daily Express and Metro.

However it has now been dropped, with the Daily Mail saying the decision “will be seen as a vindication” for its original story.

A spokesperson for the Labour Party said: “Our view remains that the reporting we complained about seriously misrepresented the nature of what took place, those buried in the cemetery and the mainstream Palestinian leaders conducting the ceremony, and these inaccuracies breached the IPSO code.

“Regrettably, confidential communication with IPSO was leaked and it was unable to trace the source or assure us it would not recur, and we considered that the complaints process was unacceptably compromised.

“We therefore decided we would not be taking this IPSO complaint any further.”

IPSO confirmed that it is no longer investigating any complaints about the relevant articles, but declined to comment on Labour’s claim that the complaints process was compromised.

Labour appeared to be referring to an email published in the Guardian earlier this month which the newspaper revealed the complaint was temporarily shelved after the party missed a deadline.

The Guardian saw an email from a Labour official to IPSO asking for “extenuating circumstances” for the case to continue nonetheless.

Picture: Reuters/Phil Noble