How a Pro-Palestinian Group Fell Foul of a Long Unused U.K. Terrorism Law

Days before the American-led invasion of Iraq, five protesters broke into a British military base, intent on disabling aircraft that were set to be deployed in bombing missions.

It was March 2003, and the group said it wanted to prevent war crimes and protect civilians. Among those who later defended them in court was a 43-year-old human rights lawyer.

His name was Keir Starmer.

In a strange echo, 22 years later, Mr. Starmer would face a similar case, but now as prime minister of Britain.

In June, activists from a group called Palestine Action broke into a Royal Air Force base, sprayed red paint into aircraft engines and damaged the planes with crowbars. Like the 2003 group, the protesters argued that their actions were a justified response to mass civilian harm — this time in Gaza.

Both cases raised serious concerns about the security of Britain’s military bases. But a very different result ensued. While the protesters in 2003 were prosecuted under criminal laws against property damage, in June, Mr. Starmer’s government announced that Palestine Action would be added to its list of banned terrorist organizations, alongside groups including Al Qaeda, Hezbollah and Atomwaffen Division, a neo-Nazi group.

It was the first time in modern British history, according to the government’s adviser on counterterrorism laws, that a protest group that does not call for violence against people had been proscribed as a terrorist organization. The decision has fueled an intense debate over the Starmer government’s attitude toward protest and free speech.

The home secretary, Yvette Cooper, who is responsible for law enforcement and national security, said that Palestine Action had put national security at risk and that it met the government’s legal definition of terrorism because those terms included “serious damage to property.” The group has repeatedly damaged facilities linked to military companies, including Elbit Systems, an Israeli weapons manufacturer, and also vandalized President Trump’s Turnberry golf resort in Scotland in March.

The origins of this moment can be traced back a quarter-century, when the legislation used to ban Palestine Action was introduced.

The Terrorism Act of 2000 was drawn up to replace years of piecemeal security laws that had largely targeted dissident Irish republican groups like the Irish Republican Army. In a 1998 document outlining its proposals, the government of Prime Minister Tony Blair said it wanted a future-proof definition that could apply to “all forms of terrorism,” voicing concerns about potential violence from Islamist extremists, nationalists and animal rights groups.

The resulting law is conspicuously broad. It defines terrorism as “the use or threat of action” that: involves serious violence against a person or endangers someone’s life, or serious damage to property; creates a serious risk to the health or safety of the public, or is designed to seriously disrupt or interfere with an electronic system.

To meet the definition, these threats or actions must be designed to influence the government or intimidate the public, and be “for the purpose of advancing a political, religious, racial or ideological cause.”

One lawmaker, Mark Fisher, called it “baffling and disturbing,” while another, Simon Hughes, said the proposed definition of terrorism “stretches the English language too far,” and added: “If someone attacks a field of corn, there is perfectly good legislation dealing with criminal damage and damage to property.” (At the time, Britain was dealing with direct action protests against genetically modified food.)

But the government, which had a large majority, overruled them. The Home Office minister at the time, Charles Clarke, told Parliament the clause was needed because of I.R.A. bombings that destroyed buildings but did not injure people as a result of advance warnings.

Another government minister at the time, Mike Gapes, rejected the idea that people protesting against genetically modified food would be prosecuted as terrorists, calling those warnings “scare-story scenarios that are designed to frighten people off from introducing effective legislation to combat terrorism.”

For a time, it seemed the concerns were indeed overblown. Until this year, no government had invoked the “damage to property” clause alone to ban a group, and its existence had largely disappeared from public debate.

Labour says it is using it now because of Palestine Action’s escalating campaign of “direct criminal action” since it was created in 2020. David Hanson, a Home Office minister, told Parliament last month the group targeted “key national infrastructure and defense firms that provide services and supplies to support our efforts in Ukraine, NATO, our Five Eyes allies and the U.K. defense enterprise.”

He accused some members of responding violently to the police or security guards who tried to stop them, and he added: “We would not tolerate this activity from organizations if they were motivated by Islamist or extreme right-wing ideologies, and therefore I cannot tolerate it from Palestine Action.”

But for several lawmakers, the ban distorts the definition of terrorism and has far-reaching and disturbing implications.

Peter Hain, a Labour former government minister who now sits in the House of Lords, argued in response to Mr. Hanson that his own direct action against apartheid in South Africa would have led to his being “stigmatized as a terrorist today” and noted that Britain’s suffragettes “used violence against property in a strategic manner to demand voting rights for women.”

Raza Husain, a lawyer representing Palestine Action, argued in the High Court in London last month that the government had not presented evidence of any risk to national security, calling its decision an “authoritarian abuse of statutory power” that “demeans the notion of terrorism.”

Now that Palestine Action is banned, any show of support for it — including wearing a T-shirt displaying its logo — can result in arrest, as can donating to the group, being a member or arranging meetings.

In July, hours after the order came into force, 29 people, including an 83-year-old priest, were arrested outside Parliament for holding signs reading: “I oppose genocide, I support Palestine Action.”

On Thursday, three people arrested at that protest became the first in England and Wales to be charged as a result of the ban, the Crown Prosecution Service said. The Metropolitan Police announced that two women, ages 53 and 71, and a 71-year-old man were being prosecuted for “showing support for Palestine Action.”

On Saturday, hundreds of protesters in London are expected to hold signs bearing the same statement as those held by protesters in July as part of a demonstration against the ban. The police said they could “expect to be arrested” and “investigated to the full extent of the law.”

Other protesters have been swept up in the policing crackdown. On July 14, Laura Murton was demonstrating in Canterbury, southeast of London, with a Palestinian flag and signs reading “Free Gaza” and “Israel is committing genocide” when she was approached by two armed police officers.

A video filmed by Ms. Murton shows an officer telling her she could be arrested for “expressing an opinion or belief that is supportive” of Palestine Action, while Ms. Murton repeatedly says she had not expressed support for the group.

One officer says they are “trying to be fair,” adding: “We could have jumped out, arrested you, dragged you off in a van.”

Ms. Murton told The New York Times she felt “intimidated” into giving her details to the officers, and only found out she was not being investigated for any offense when she read news media coverage of the episode.

“When you give these additional sweeping powers,” she said, “we end up in a situation where we have people in the police who make broad interpretations of the law.”

On July 30, Palestine Action won permission from the High Court to bring a legal challenge against the ban, but the case will not be heard until November at the earliest. The judge, Martin Chamberlain, said in his ruling that the “police and others appear to have misunderstood the law on some occasions,” and that their actions were “liable to have a chilling effect on those wishing to express legitimate political views.”

Milo Comerford, who has been researching the evolution of counterterrorism in Britain at the Institute for Strategic Dialogue, a research institute in London, told The New York Times that it was “very clear how the Terrorism Act related to the threat landscape” in the era dominated by Al Qaeda after the Sept. 11, 2001, attacks. But he said the law was “designed to deal with very different” types of organization than Palestine Action.

Mr. Comerford questioned whether the government had “effectively made the case” for using “extraordinary” powers against the group. Numerous Palestine Action activists had previously been prosecuted under criminal damage laws.

In an earlier ruling on the case, Justice Chamberlain acknowledged that designating Palestine Action as a terrorist group “may have wider consequences for the way the public understands the concept of ‘terrorism’ and for public confidence” in Britain’s counterterrorism laws.

But he added: “If it is problematic that those who use or threaten action which involves serious damage to property but do not target or aim to endanger people are ‘terrorists,’ the problem lies with the statute and has existed for 25 years.”