A British appeals court on Monday upheld the government's decision to ban Palestine Action as a terrorist organization, dealing a setback to the pro-Palestinian activist group after judges found the designation was lawful.

Chief Justice Sue Carr said the group went far beyond staging non-violent demonstrations to launch destructive attacks on defense companies, banks, and a military base.

The ruling overturned a February decision by three senior High Court judges who found that, despite the group promoting its political cause through some crimes, the scale of its activities did not warrant a ban.

Five judges on the appellate panel said the lower court understated the latitude then-Home Secretary Yvette Cooper had in banning the group and that her decision was "justified and proportionate” when balanced against free expression rights.

Palestine Action co-founder Huda Ammori said the group will fight the decision all the way to the Supreme Court and the European Court of Human Rights to overturn "one of the most extreme attacks on free speech and the right to protest in modern British history.”

The government outlawed the group after activists broke into a Royal Air Force base in June 2025 to protest British military support for Israel’s genocidal attacks in Gaza, which killed over 73,000 Palestinians, mostly women and children.

Supporters of Palestine Action and civil liberties groups said arrests of peaceful protesters had trampled on free speech and protest rights.

The ban was never lifted during the appeal, and more than 3,300 people have been arrested at protests for actions as simple as holding signs saying, "I oppose genocide. I support Palestine Action.”

More than 700 have been charged under the U.K.’s Terrorism Act, although no one has yet been convicted, as the cases were put on hold pending the appellate decision. A judge will decide on June 30 whether those court cases proceed.

The backlog is likely to keep growing as protesters appear undeterred following the ruling. Police arrested many in the large crowd of Palestine Action supporters outside the Royal Courts of Justice.

The group, Defend Our Juries, criticized the ruling and said it would lead to more police resources being wasted locking up peaceful protesters.

"It appears the courts have been instrumentalized to suppress opposition to genocide, when they should be doing the precise opposite,” the group said in a statement issued after the ruling.

Carr said the court understood that the ruling could create a "chilling effect” to dissuade law-abiding people from supporting the Palestinian cause for fear of being swept up with supporters of Palestine Action.

"It is one thing for people voluntarily to hold a placard supporting Palestine Action which they know to be a proscribed organization. That is a criminal act,” Carr wrote. "As a matter of law, the proscription decision will not prevent public expressions of support for the Palestinian cause or opposition to Israel and to the Israeli Defense Force.”

Palestine Action has carried out direct action protests at military and industrial sites in the U.K. since it was formed in 2020, including breaking into facilities owned by Israeli weapons manufacturer Elbit Systems U.K.

The group has been around since at least 2020, when it launched its first attack on Elbit’s London headquarters by smearing red paint on the building. But it has grown in prominence on the streets since Israel launched its genocidal offensive in Gaza.