The Metropolitan Police could face hundreds of claims for compensation from Extinction Rebellion activists after the group won a High Court challenge over a protest ban.
The force imposed a blanket ban across London last month, prohibiting any assembly of more than two people linked to XR’s Autumn Uprising action.
But two senior judges ruled on Wednesday that the decision to impose the ban, made under Section 14 of the Public Order Act, was “unlawful”.
Lawyers who acted for XR said after the ruling that the Met now faces claims for false imprisonment from “potentially hundreds” of protesters who were arrested after the ban was imposed.
In 10 days of protests to call for urgent action on climate change and wildlife losses, which started on October 7, XR activists shut down areas around Parliament and the Bank of England and targeted London City Airport and Government departments.
The Met used Section 14 of the Public Order Act initially to restrict the protest action to Trafalgar Square, but following “continued breaches” of the order officers moved in to clear the area.
The force said 1,828 people were arrested during the protests, and more than 150 were charged with offences.
The final cost of the operation is not yet known, but currently stands at more than £24 million.
Announcing their judgment in London, Lord Justice Dingemans and Mr Justice Chamberlain said the Met had no power to impose the ban because the Act does not cover “separate assemblies”.
Lord Justice Dingemans said: “Separate gatherings, separated both in time and by many miles, even if coordinated 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.”
However, the judges noted there are powers within the Act which may be used lawfully to “control future protests which are deliberately designed to ‘take police resources to breaking point’” – one of XR’s stated aims.
Jules Carey, a solicitor from Bindmans law firm who represented XR, said: “The ban on the XR protest was hastily imposed, erratically applied and has now been unequivocally declared unlawful by the High Court.
“The police have powers to impose conditions to manage protests but not to ban them.
“This judgment is a timely reminder to those in authority facing a climate of dissent – the right to protest is a long standing fundamental right in a democratic society that should be guarded and not prohibited by overzealous policing.”
The Metropolitan Police said it will “carefully consider” the ruling.
Met Assistant Commissioner Nick Ephgrave said the decision was “not taken lightly” and came after more than a week of disruption to communities across the capital.
He said the various protests coordinated by XR created “unacceptable and prolonged disruption to Londoners” and the force believes the decision to impose the condition was “both reasonable and proportionate”.
Mr Ephgrave 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.
He added: “There is no criticism from me of the decision to impose the condition, which was made with good intent and based upon the circumstances confronting the command team at the time.
“It did in fact result in the reduction of the disruption. Nevertheless, this case highlights that policing demonstrations like these, within the existing legal framework, can be challenging.”
The legal challenge was brought on behalf of XR by a number of people including Green Party politicians Baroness Jones, Caroline Lucas MP and Ellie Chowns MEP – who was arrested after the ban came into force.
Speaking outside the Royal Courts of Justice after the ruling, Ms Chowns said: “This is an enormous victory for the right to assembly and protest, which are cornerstones of democracy.
“It is time to act – not to outlaw the alarm, but to listen to it and to tackle the climate emergency with the urgency it deserves.”
Baroness Jones said: “This is a historic judgment, not just for the future of policing protests, but when reviewing previous actions by the police, where the same powers have been used.”
XR’s stated tactics are to cause “maximum disruption” and to overwhelm the capacity in police custody, including by refusing bail after being arrested.