HUNDREDS of climate change activists could sue the Metropolitan Police after the High Court ruled today that the force’s ban on Extinction Rebellion (XR) was unlawful.

A blanket ban was imposed across London last month prohibiting any assembly of more than two people linked to the environmental group’s Autumn Uprising action.

The decision to impose the ban, made under Section 14 of the Public Order Act, was ruled unlawful by two senior judges today — who said the force had “no power” to prohibit gatherings but could “merely impose conditions” on them.

Lawyers representing XR said the Met now faces claims for false imprisonment from “potentially hundreds” of protesters who were arrested after the illegal ban was imposed.

Solicitor Jules Carey from the 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.”

Over 400 XR activists were arrested during the four-day ban. Those who have been charged under Section 14 can now sue the Met and may be entitled to compensation.

Journalist and environmentalist George Monbiot, who was arrested under the ban, said: “This judgment is a vindication of those who have sought to defend our crucial right to protest.

“Non-violent civil disobedience is essential to democratic politics — in fact there would be no democratic politics without it.

“The attempt by the Metropolitan Police to shut down civil protest was a direct assault on democracy. I am delighted it has been struck down.”

Over 1,800 people were arrested during the fortnight of protests and more than 150 were charged.

Labour MP Clive Lewis, one of the claimants who brought the judicial review to court, said: “Peaceful protest is an essential guarantor of a free and democratic society, so I welcome [the] judgment.

“XR is sounding the alarm about the climate and ecological emergency. Rather than trying to block our ears by shutting down their protests, we should be reacting to the danger they’re alerting us to.

“Averting that danger requires urgent and radical change, not the criminalisation of peaceful protest.”

Labour’s shadow attorney general Shami Chakrabarti said: “It is no surprise that such a disproportionate and blanket ban on even the most peaceful of protesters in our capital was unlawful.

“A Labour government will act both to protect peaceful dissent and the planet.”

The Metropolitan Police said it will “carefully consider” the ruling.