Three climate activists have been convicted of "interference with key national infrastructure" by marching in the road in west London for 20 minutes, in the new offence's first test at trial.
Phoebe Plummer, Chiara Sarti and Daniel Hall were the first defendants to face a jury trial on the new section 7 of the Public Order Act 2023, which bans any act preventing harbours, airports, railways or roads "from being used or operated to any extent".
Critics have called the law repressive, and claimed that it gives authorities a licence to crack down on virtually any protest at their discretion.
The defendants had sought to persuade the jury that convicting them under the new law could criminalise a swathe of legitimate protest. But after jurors were directed to only take into account whether or not the protest had caused "significant" disruption to the roads, they found the defendants guilty in an 11-1 majority verdict.
Over a five-day trial, Southwark crown court heard that on 15 November last year Plummer, Sarti and Hall took part in a slow march protest along Earls Court Road as part of the Just Stop Oil campaign, which calls on the government to ban new licences for oil and gas exploitation in the UK.
The court heard the protest had caused long tailbacks, including on the Cromwell Road, part of the A4, and reaching as far away as the Hammersmith flyover, with traffic held up for several hours.
In their defence, Plummer, Sarti and Hall said their protest was designed to minimise the amount of disruption caused to drivers, while still causing enough to gain media coverage of their demand that the government introduce a ban on new licences for oil and gas exploitation.
Plummer told the jury: "I want to prevent the massive disruption to all of us, from flooded roads, homes, and fields, from heat that melts roads and runways and is already killing and displacing millions around the world." Hall asked: "Isn't it more reckless to spend the final two to three years we have left to avoid climate breakdown signing petitions and politely protesting by the side of the road?"
The trio will be sentenced on 3 July. The maximum penalty is 12 months imprisonment, an unlimited fine or both.