A prominent climate protester called on volunteers to bring the M25 to a standstill for four days and “cause the biggest disruption in modern British history”, a court in London has heard. Roger Hallam, along with Louise Lancaster, Daniel Shaw, Cressida Gethin, and Lucia Whittaker-de-Abreu, are alleged to have recruited and organised activists to climb gantries “at strategic intervals” along the motorway on four days in November 2022. “This, in turn, caused lengthy tailbacks, hours of delays, and widespread disruption,” Jocelyn Ledward KC said, as she opened the crown’s case on the first day of their trial at Southwark crown court on a charge of conspiracy to cause a public nuisance. “In short, a public nuisance depriving very many members of the public of the ability to exercise their right to use the motorway to go about their daily activities with, for some, serious inconvenience and more for their personal lives and for their businesses. “The prosecution allege that these were not spontaneous or coincidental events, but the culmination of a plan, carefully orchestrated by these five defendants and others, over several weeks at least. “A plan which was designed to bring about exactly that consequence; the mass disruption and inconvenience intended to attract publicity to their cause and to attempt to force a change in government policy.” The four days of the campaign caused disruption leading to a “notional economic loss” of almost £750,000, in addition to a cost of almost £1m to the police, Ledward said. She said those caught in heavy traffic as a result of the protest included children on their way to special needs schools, mourners on their way to a funeral, a cancer patient who missed their appointment, and a woman with a young baby who missed her flight, as well as thousands of other motorists. The court heard that Whittaker-de-Abreu and Gethin were apprehended on their way to climb gantries during the brief campaign of disruption, and “had every expectation” that “they would be arrested and they would be likely to face legal consequences”. “Not so the others who were involved in the grand plan, who hoped, no doubt, to remain within the shadows,” Ledward said. She said police also had collected evidence showing Lancaster had booked Airbnb “safe houses” for the plan, and had bought climbing equipment. One piece of prosecution evidence was a recording of an online meeting over Zoom, infiltrated and recorded by a tabloid newspaper journalist, in which each of the five defendants spoke to potential recruits days before the protest began. In parts of the video, played by Ledward to the jury, Shaw introduced the meeting and told viewers: “We’re quite near to the go date … but if you feel you’re up for a spicy action in the near future and you have got a few days to spare, by all means stay with us.” Whittaker-de-Abreu said it would be “the most disruptive action that anyone in the climate movement has ever done”. Lancaster called it “the ultimate action that you can really feel that you are making a difference”. Hallam said: “I’m saying that if you’re going to do one action this year, at this moment in time … this is the time to step up and do an action … if it goes to three, four days you’re in the ball park of the biggest disruption in British modern history. “And that’s what we need to do, let’s be really clear about that. We are not going to influence government policy by just going through the motions.” The trial continues.