Five supporters of the Just Stop Oil climate campaign who conspired to cause gridlock on London’s orbital motorway have been sentenced to lengthy jail terms by a judge who told them they had “crossed the line from concerned campaigner to fanatic”.

Roger Hallam, Daniel Shaw, Louise Lancaster, Lucia Whittaker De Abreu and Cressida Gethin were found guilty last week of conspiracy to cause a public nuisance for coordinating direct action protests on the M25 over four days in November 2022.

Hallam received a five-year sentence on Thursday, while the other four were each sentenced to four years.

The sentences are thought to be the longest sentences even given in the UK for non-violent protest, exceeding those given to the Just Stop Oil protesters Morgan Trowland (three years) and Marcus Decker (two years and seven months) for scaling the Dartford Crossing.