‘I felt this was an abuse of power’: the climate activist who took on the law and won

Two days before Trudi Warner faced court under threat of a contempt of court prosecution, she fell off her bike and ruptured the tendons in her hand.

Now the hand is black and blue, tightly bandaged, and requires surgery. It is an indication that 69-year-old Warner, who spent her working life as a child social worker and has committed her retirement to climate action, is not as tough and unflappable as her demeanour suggests.

“I cycled back from a friend’s house and all this was going through my head,” she said. “My mind wasn’t really focused on what I was doing. I was very tired, all of this was weighing on me, and I came off the bike.”

For a year government lawyers pursued Warner, determined to prosecute her for contempt of court – which carries a maximum two-year jail sentence – for a lone, silent protest in March last year in which she held up a placard highlighting the independence of juries.

It was a protest outside a London court that was born out of the increasing restrictions being placed on defendants in climate trials, which in effect removed their ability to explain their motivations for their peaceful but disruptive actions to a jury.

In a series of trials, individuals have been banned from mentioning to the jury the words “climate change”, the history of the civil rights movement or the issue of fuel poverty.

Those individuals who ignored the restrictions imposed by Judge Silas Reid at inner London crown court were sent to jail for contempt of court as a result.

“The state had been losing these climate cases until this point, and I think these restrictions were a pushback,” said Warner. “They left individuals with no defence in court.

“I just felt that this was an abuse of power, a miscarriage of justice. I thought, why are we having jury trials where defendants are supposed to tell the truth, the whole truth and nothing but the truth, and not letting defendants speak to the jury about their actions? It made no sense. It felt like a scam. I wanted to challenge that.”

Her challenge last March was solitary, and mute. Its aim was to highlight a principle in UK law that juries can acquit defendants on their conscience, even in the face of facts that suggest their guilt and a judge’s direction.

Known as jury equity, its most famous enactment was in 1670 at the central criminal court in the Bushel case, when a jury refused a judge’s orders to convict two Quakers of unlawful assembly despite being jailed and denied food and water by the judge. It was a case that cemented the independence of juries and is celebrated with a marble plaque in the corridors of the Old Bailey.

In a hat tip to the Bushel case, Warner made a handwritten sign which read: “Jurors, you have an absolute right to acquit a defendant according to your conscience,” and stood outside the side entrance to inner London crown court on the opening day of a trial of Insulate Britain campaigners.

“I was like a human billboard. I said nothing, I didn’t engage with anyone, even if they came up and asked me questions,” she said.

But the protest had been noted by court officials who reported her to Reid. The following day Warner was handcuffed, locked up in the court’s custody unit, and later taken into the dock to face the judge.

Rather than make the decision himself, Reid referred her case to the government’s highest law officer, the attorney general, for a decision on whether to charge her with contempt of court.

Over the weeks and months that followed, Warner says, she felt like David facing Goliath in a battle that pitched a team of government law officers, paid for by taxpayers, against a lone woman in her late 60s.

“I got letters saying: ‘His Majesty’s solicitor general versus Trudi Ann Warner,’” she told the Guardian. “They sent a 133-page indictment on me. A hundred and thirty-three pages … all those government lawyers working on this for months – I mean just how much public money have the government spent?”

As the weeks of waiting went on, in May last year Warner fulfilled a promise to help a sheep farmer in Scotland with lambing. Living on the Isle of Eigg in a farmhouse with no wifi, she was contacted by a friend who suggested she find an internet connection and check her phone the following day.

Related: Sunak’s weakening of climate targets ‘retrograde’, says former Tory minister

“I went to the village hall and used their wifi the next day. When I checked my phone I saw an image of about 20 people outside inner London crown court. They were all holding placards saying: ‘If you prosecute Trudi, prosecute us too.’ When I saw that I broke down, to see all those people prepared to be prosecuted for contempt of court as well. It was an astonishing and moving act of solidarity,” she said.

It is the support of others involved in climate action that has helped Warner as she faced a possible prison term for contempt for her actions. As the case against her was thrown out on Monday, ensuring her liberty and rejecting the government argument to prosecute her, supporters were again outside court.

“This decision is empowering for people who have cases coming to court,” said Warner. “It is a victory in one battle. It has restored my faith a little in British justice. I was lucky, I had a balanced, independent and deeply thoughtful judge and I am grateful to him.”