More than 1,200 artists, athletes and academics have condemned the “injustice” of sentences handed to five Just Stop Oil activists for peaceful protests.

In a letter to Attorney General Richard Hermer KC, the high-profile figures backed millionaire Labour donor Dale Vince and broadcaster Chris Packham’s call for an urgent meeting to discuss “the jailing of truth tellers and their silencing in court”.

It comes after Roger Hallam, 58, was jailed for five years after being found guilty of conspiracy to cause a public nuisance for his involvement in a protest that disrupted the M25 in London for more than four days in 2022.

Cressida Gethin, 22, Daniel Shaw, 38, Lucia Whittaker de Abreu, 35, and Louise Lancaster, 58, were jailed for four years over the demonstration, which saw 45 people climb on to gantries over the motorway.

Just Stop Oil protests
The M25 protests took place over four days (Just Stop Oil/PA)

The jail terms are thought to be the longest sentences ever given for peaceful protest and exceed those handed to two fellow Just Stop Oil protesters for scaling the Queen Elizabeth II Bridge on the Dartford Crossing in October 2022.

Prime Minister Sir Keir Starmer has faced calls to intervene in the case while UN human rights commissioner Volker Turk described the sentences as “deeply troubling”.

Artist Dame Tracey Emin, Coldplay frontman Chris Martin, film director Danny Boyle, author Sir Philip Pullman, singer Annie Lennox and actor Toby Jones were among those who signed the open letter in support of Mr Dale and Mr Packham, who called for the meeting with the Attorney General last week.

Others who put their name down included top human rights lawyer Sir Geoffrey Bindman KC, former Archbishop of Canterbury Rowan Williams and former Labour leader Jeremy Corbyn.

They described the jail terms handed to the activists, known as the Whole Truth Five, as “one of the greatest injustices in a British court in modern history”.

The letter said: “With prisons at breaking point and the new government acting urgently to address this, how can these sentences be seen as anything other than insanity?

Restore Nature Now protest – London
Chris Packham condemned the jail terms (Aaron Chown/PA)

“The sentences, ranging from four to five years, are higher than those given to many who commit serious sexual assault.

“The defendants were denied the right to explain to a jury why they took the action they did, making a mockery of the right to a fair trial, with the judge saying that the Crown Prosecution’s agreed facts on climate collapse — including that the world has gone beyond 1.5C for 12 consecutive months — were neither here nor there.”

The signatories argued that the non-violent protesters were “fulfilling a necessary service by alerting the nation to the grave risk we all face, as scientists in their droves express their fear that many of the Earth’s systems are already at breaking point”.

During the trial at Southwark Crown Court, prosecutors alleged the M25 protests led to an economic cost of at least £765,000 while the cost to the Metropolitan Police was more than £1.1 million.

They also allegedly caused more than 50,000 hours of vehicle delay, affecting more than 700,000 vehicles, and left the M25 “compromised” for more than 120 hours.

A spokesperson for the Attorney General’s Office said: “Decisions to prosecute, convict and sentence are, rightly, made independently of Government by the Crown Prosecution Service, juries and judges respectively.

“The Attorney General has no power to intervene in these cases.”