"It is the end of soup on van Goghs, cornstarch on Stonehenge and slow marching in the streets," the group said in a statement, claiming that it had succeeded in its initial aim to stop Britain approving new oil and gas projects.

Founded in 2022, Just Stop Oil rose to prominence when its orange-clad activists staged headline-grabbing protests to raise awareness about the danger to the climate posed by greenhouse gas emissions from fossil fuels.

Stunts included targeting Vincent van Gogh's "Sunflowers" painting with tomato soup and daubing Stonehenge with orange paint powder.

"Three years after bursting on the scene in a blaze of orange, at the end of April we will be hanging up the hi vis (high-visibility vests)," the group said on Thursday.

"Just Stop Oil's initial demand to end new oil and gas is now government policy, making us one of the most successful civil resistance campaigns in recent history."

Since coming to power in July 2024, the UK Labour government has halted new oil and gas exploration licences in the North Sea -- but has also distanced itself from the group.

Just Stop Oil said it would hold a final rally in London's Parliament Square on April 26, and "continue to tell the truth in the courts, speak out for our political prisoners and call out the UK's oppressive anti-protest laws".

It said the demonstration was intended as "a lower-risk action" designed to avoid arrests and encourage more people to take part.

Dozens of Just Stop Oil protesters have been arrested since the group's foundation and the group told AFP 15 were currently in jail.

Earlier this month, a court in London cut by one year a five-year jail term imposed on Just Stop Oil's 58-year-old co-founder Roger Hallam accused of conspiracy for planning to block the M25 motorway in an online call.

- 'A different approach' -

Just Stop Oil confirmed its change of strategy in a call with AFP and said it was working on a new project, but did not provide details.

"As corporations and billionaires corrupt political systems across the world, we need a different approach," it said.

"We are creating a new strategy to face this reality and to carry our responsibilities at this time. Nothing short of a revolution is going to protect us from the coming storms."

Over the years the activists' stunts have drawn condemnation from politicians, police and some sections of the public.

"I'm sure ... plenty of members of the public will be happy to hear that they may be causing less disruption in the future," a spokesperson for British Prime Minister Keir Starmer told journalists on Thursday.

He denied however that the government had handed Just Stop Oil "a win".

"We have been very clear when it comes to oil and gas that it has a future for decades to come in our energy mix," he said.

Will McCallum, co-executive director of Greenpeace UK, defended the group's work.

"Just Stop Oil paid a heavy price for raising their voices at a time when politicians and corporations are trying to silence peaceful protesters -- in the streets and in the courts," he said.

"We must not allow our hard-won right to protest to be stripped away, because it is the right that all other rights depend upon."

Tactics used by the group have included using slow marches to disrupt traffic, blocking major roads, and targeting sporting events, theatre performances, art galleries and heritage sites.

Just Stop Oil activists emptied soup cans over the glass protecting "Sunflowers" at London's National Gallery in October 2022, while protesters targeted the ancient Stonehenge monument in June 2024.

In July 2023, Just Stop Oil protesters disrupted tennis matches at the Wimbledon championships, while in May 2024, two activists in their 80s took a hammer and chisel to the glass case surrounding the Magna Carta at the British Library, holding up a sign that said: "The government is breaking the law."