A leading human rights barrister has won an appeal against his referral for contempt of court over his closing speech during a trial of Palestine Action activists.

Rajiv Menon KC was accused of breaching the judge’s directions in the trial of six people for a 2024 direct action protest at an arms factory of the Israeli subsidiary Elbit Systems UK in Filton, near Bristol.

The proceedings against Menon – who previously worked on the Stephen Lawrence inquiry, the inquests of victims of the Hillsborough disaster and the Grenfell Tower inquiry – were believed to be the first brought against a barrister in respect of a jury speech in living memory, possibly ever. On Tuesday, the court of appeal allowed the barrister’s challenge to them.

Menon’s solicitor, Jenny Wiltshire, from Hickman & Rose, said: “Rajiv is delighted that the court of appeal has found in his favour and decided that the Filton trial judge did not have the power to refer him directly to the high court to be prosecuted for contempt of court and that the high court did not have the power to accept the reference in the absence of an application by the attorney general in the public interest.”

She said he was grateful to his lawyers and others who supported him during a difficult time and “hopes that this is now the end of the matter. This unprecedented attempt to criminalise lawyers for doing their job and representing their clients fearlessly should never be repeated”.

The trial judge, Mr Justice Johnson, referred Menon because he considered that the barrister had contravened his ruling in which he forbade lawyers from inviting the jury to disregard the court’s rulings of law or to apply the principle of jury equity – the right of a jury to acquit on the basis of conscience regardless of the judge’s directions – or to inform the jury of it.

None of the defendants were convicted of any offence but they were retried and four were convicted last week.

The high court had directed that a summons for contempt be drawn up and served on Menon after a referral from Johnson. The court of appeal said Johnson should reconsider the matter in the light of its ruling.

Defend Our Juries said the fact that contempt proceedings were ever brought against Menon “should deeply concern everyone who cares about the rule of law”.