Environmental activism group Extinction Rebellion has won a challenge in Britain’s High Court against police over a London-wide ban on protests.

Two senior judges have ruled that London's police force had no power to impose the ban under Section 14 of the Public Order Act because that part of the law doesn't cover multiple gatherings.

Activists protested at sites around central London for 10 days in October, demanding more urgent action to counter global warming.

The police say 1,832 people were arrested.

Many protesters were pre-emptively detained under the ban before they could take any action.

Law firm Bindmans, which represented the activists, say police now face claims for false imprisonment.

Tobias Garnett, a human rights lawyer in Extinction Rebellion's Legal Strategy team, said the group was “delighted” with the court's decision.

“It vindicates our belief that the police's blanket ban on our protests was an unprecedented and unlawful infringement on the right to protest,” he said.

“Rather than wasting its time and money seeking to silence and criminalise those who are drawing its attention to the climate and ecological emergency, we call on the Government to act now on the biggest threat to our planet.”

The High Court also ruled that the Public Order Act could be used to control future protests that are deliberately designed to "take police resources to breaking point."

The Met had argued the ban was the only way of tackling disruption caused by protests.

In the ruling, Lord Justice Dingemans said: "Separate gatherings, separated both in time and by many miles, even if co-ordinated under the umbrella of one body, are not a public assembly within the meaning of... the Act. The XR autumn uprising intended to be held from October 14 to 19 was not therefore a public assembly... therefore the decision to impose the condition was unlawful because there was no power to impose it under... the Act."