A Just Stop Oil protester has been convicted of causing a nuisance by climbing onto a gantry over the M25.

Cambridge University music student Cressida Gethin, 22, scaled the gantry to protest the UK reaching its hottest temperature on record, 40C.

Speaking outside Isleworth Crown Court after the verdict she said she does not regret the protest and “will not back down”.

On Monday a jury found Gethin guilty of causing a public nuisance contrary to the Police, Crime, Sentencing and Courts Act 2022, by a majority of 10 to two.

During her trial the court heard the protest on July 20 2022 delayed 3,923 British Airways passengers’ journeys.

BBC broadcaster Chris Packham told the jury he was stuck in four to five hours of traffic.

Speaking outside the court on Wednesday after giving evidence in the trial, Packham said he supports Gethin’s cause.

He said: “What makes a music student aged 22, with her whole life ahead of her, do something as precarious, physically dangerous and now, potentially in terms of an impact on her life, dangerous?

“Well, I think I know the reason and I think everyone else knows the reason.

“She maybe doesn’t have her whole life ahead of her in the way that she might desire because of the threat of climate breakdown, and the message that she was desperate to impart is that we need to address this issue.

“One of the things we need to do is transition rapidly away from our dependence on fossil fuels and move into renewables, and that is something which I support obviously.”

Gethin did not dispute scaling the gantry but argued the consequences did not amount to the charge.

In her closing statement on Thursday, Gethin, who was self-represented, told the court: “If you believed that the protest causing the delays was intended to create meaningful, positive change, would you have defined the delay as ‘serious inconvenience’?

“Or would you have experienced it as a proportionate and manageable inconvenience? Given that the policy change the protest was seeking to achieve would literally save thousands of lives in the coming decades.”

However, Judge Hannah Duncan said “evidence about climate change wasn’t admissible or relevant”.

On Friday, Judge Duncan said she believed the average person would consider the climate crisis “far more serious” than a nuisance, but that “that’s not what they (the jury) are considering”.

After the verdict, Gethin said outside the court: “I could have pleaded guilty at an earlier stage.

“It would have given me some credit off my sentencing, but I felt very strongly that I needed to stand up in front of a jury of my peers and tell them why I had done what I had done.

“The majority verdict means that at least me speaking about why I had done what I had done did touch some hearts and minds.

“I will continue doing the best I possibly can to divert climate and social collapse, I don’t know what that will look like exactly, but I absolutely will not back down as a result of this.”

Asked if she regretted the protest on the gantry, she said: “Never, never – it was reaction to probably the worst effects of the climate crisis we’ve experienced in the UK; it absolutely had to be done and I stand by that”.

Gethin is due to be sentenced on May 3.