(Adds comment from Extinction Rebellion, police)
LONDON, Nov 6 (Reuters) - Extinction Rebellion climate-change activists won a legal challenge in London's High Court on Wednesday against a police-imposed blanket ban on protests during its "Autumn Uprising" in the British capital in October.
The court said separate gatherings, even if coordinated by one organisation, could not be defined as a single "public assembly" and the officer who set the ban was not present at the scene.
Therefore barring any Extinction Rebellion protest in London other than at Trafalgar Square was unlawful and would be quashed, it said.
Extinction Rebellion blocked roads, targeted financial institutions, sprayed paint on the government's Treasury and disrupted transport during two weeks of direct action.
It aimed to force the government to transform the current economic model so that radical action can be taken against climate breakdown, biodiversity loss and the risk of social and ecological collapse.
Police, however, said the protests were hugely disruptive to London and action planned on the London Underground posed a threat to the safety of customers and staff, according to the court ruling.
Ellie Chowns, a Green member of the European Parliament who was arrested while the ban was in place, said the ruling defended the right to peaceful assembly and public protest.
"The judgment in our favour shows that the police clearly overstepped the mark when they imposed a blanket ban on any XR (Extinction Rebellion) related protest," she said.
London's Metropolitan Police Service said it was disappointed by the judgment.
Assistant Commissioner Nick Ephgrave said the decision to ban the protests was not taken lightly.
"After more than a week of serious disruption in London both to communities and across our partner agencies, and taking account of the enormous ongoing effort by officers from the Metropolitan Police Service and across the UK to police the protest, we firmly believed that the continuation of the situation was untenable," he said.
"I want to be clear; we would not and cannot ban protest. The condition at the centre of this ruling was specific to this particular protest, in the particular circumstances at the time."
The police said 1,828 people were arrested in 10 days of protest, with 165 charged by 6 Nov. The policing cost stood at over 24 million pounds as of 30 Oct.
Extinction Rebellion said more than 400 of its activists were arrested during the four-day ban, and those not charged with other offences could now sue the police for false imprisonment and could be entitled to compensation. (Reporting by Paul Sandle; editing by Michael Holden/Guy Faulconbridge)