LONDON — A British court on Friday rejected appeals by most of a group of environmental activists who were jailed for actions including stopping traffic, blocking an oil facility and splashing a Vincent van Gogh painting with soup.

The Just Stop Oil protesters had challenged what they alleged were “manifestly excessive” prison terms of between 15 months and five years for disruptive but peaceful actions. The group argued that the jailed protesters are political prisoners who were “acting in self-defense and to protect our families and communities.”

Three Court of Appeal justices rejected claims by 10 of the activists but reduced the sentences of six others who were jailed over 2022 demonstrations that saw protesters climb gantries above a busy highway. They include Roger Hallam, the co-founder of eco-activist organization Extinction Rebellion and spinoff group Just Stop Oil, who had his five-year sentence reduced to four years.

The claimants’ lawyer, Raj Chada, said “the small reduction in the case of Roger Hallam recognizes the extraordinarily excessive sentences that continue to be given out to protesters in England.

“It is, however, extremely disappointing that many of the other sentences were upheld,” he said. “No country in Europe gives such draconian sentences for peaceful protests, proving we are out of kilter with the rest of the civilized world.”

He said the group was considering taking the case to the U.K. Supreme Court.

The 10 whose appeals failed included protesters sentenced for digging tunnels under the road leading to an oil terminal in southeast England and throwing soup onto the protective glass over Van Gogh’s “Sunflowers” at London’s National Gallery.

As Chief Justice Sue Carr read out the ruling, several campaigners in the courtroom stood and turned their backs, wearing T-shirts that read “Corruption in Court.”

The Conservative U.K. government that lost power in July 2024 toughened anti-protest laws in response to eco-activists who blocked roads and bridges, glued themselves to trains, splattered artworks with paint, sprayed buildings with fake blood and doused athletes in orange powder to draw attention to climate change.

The then-government said the laws prevented extremist activists from hurting the economy and disrupting daily life.

Civil liberties groups argued that it weakened the right to peaceful protest. They have urged the center-left Labour Party government, elected in July, to ease the restrictions on protest imposed by its predecessor.

“Despite some modest reductions, these sentences are still unprecedented and they still have no place in a democracy that upholds the right to protest,” said Areeba Hamid, co-executive director of Greenpeace UK, which supported the appeals.

“If you care about anything any corporation or anyone in a position of power is doing, or should be doing, you should be incredibly concerned about your freedom to speak out.”