Restrictions placed on non-violent climate protesters who have been tried in criminal courts were part of a “deeply concerning” “pincer movement” narrowing their rights to free expression, leading lawyers have told the Guardian. Three Insulate Britain activists are serving jail terms for contempt of court for breaching rulings made by a judge that they were not to mention the climate crisis, fuel poverty or the history of the peaceful civil rights movement to juries. The three – David Nixon, Amy Pritchard and Giovanna Lewis – were jailed after addressing the juries at separate trials to explain their motivation for taking direct action. They were on trial for public nuisance for taking part in a roadblock in the City of London in October 2021 as part of a campaign by Insulate Britain which says it wants to pressurise the government to insulate UK homes to reduce carbon emissions. Nixon was convicted of public nuisance. The jury failed to reach verdicts in the trial of Lewis and Pritchard and a decision is due on 31 March on whether a retrial will take place. The rulings were made by Judge Silas Reid at Inner London crown court. Addressing the juries, the judge said the trials were not about climate change, or whether the actions of Insulate Britain and similar organisations were to be applauded or condemned, but whether or not the protesters caused a public nuisance. The defendants’ motivations for acting the way they did had no relevance, he said. The Guardian understands similar rulings restricting freedom of expression defences available to peaceful protesters have been made at trials in other courts. Katy Watts, a lawyer at advocacy organisation Liberty, said it was “deeply concerning” to see protesters imprisoned just for mentioning the reason for their actions. “We all have the right to stand up for causes we believe in. But we have seen a kind of pincer movement going on over the scope of convention rights in protest cases, which [is] increasingly narrowing our rights,” she said. “The way that some protest trials, in particular those involving climate activists, have been managed has interfered with defendants’ rights to freedom of expression.” Nixon, a care worker from Barnsley, was jailed for eight weeks for contempt of court after trying to explain to the jury at his trial the connection between insulation and tackling the climate crisis. Before being stopped by the judge, he said: “You’ve not been able to hear these truths because this court has not allowed me to say them.” Nixon said later in court he had found the inability to explain to the jury why he had taken direct action “soul-destroying”. He was told he would serve half of his term in prison. Reid told him the criminal courts were solely there to establish whether the prosecution had proven the guilt of defendants. “You said the court is not upholding what it is there to uphold,” he said. “You were wrong about that. This court is here to determine whether people have committed crimes.” Pritchard and Lewis were each jailed last Friday for seven weeks for contempt. Lewis, a councillor from Dorset, told the court why she had breached the judge’s ruling. “There are thousands of deaths every year in the UK from fuel poverty, and thousands of deaths around the world due to climate change. There is no choice but to give voice to truth and to not be silenced,” she said. Pritchard said: “Lack of political action means that ordinary people have to act.” But the judge said the women each had disdain for the judicial process and had breached his ruling. “You have each been given the opportunity to apologise. Neither of you took that opportunity,” he said. “My ruling was made because there was no relevance to the matters that the jury needed to decide. The public have rights as well as protesters.” Tom Wainwright, a barrister from Garden Court chambers, said the growing concern being expressed at the removal of defences for protesters indicated the law may not have got the position right. “The concerns raised about people’s ability to explain their motivations, and the consequences when they did, will, I think cause people to look again at this,” Wainwright said. He went on: “A lot of protest cases all come down to the big question of where the boundary of freedom of expression lies. “It is not a trump card which overrides the rights of others. A balance needs to be struck and I think it is one of the things a jury is ideally suited to consider.”