A LONDON-wide police ban on Extinction Rebellion protests was "wholly uncertain, an abuse of power and irrational", High Court judges have heard.

The Metropolitan Police imposed a blanket ban across the capital last week, making any assembly of more than two people linked to XR's Autumn Uprising action - which ended on Saturday - illegal.

At a hearing in London on Thursday, lawyers for XR argued that the ban, made under Section 14 of the Public Order Act, was unlawful because the Met went beyond its powers by prohibiting "multiple assemblies, both ongoing and intended".

Phillippa Kaufmann QC said: "The condition imposed was wholly uncertain, an abuse of power and irrational because it purported to apply to future assemblies, when there is no power to impose such a condition.

"Insofar as it applied to existing assemblies, because these were not clearly identified - even by geographical location - it was impossible for any individual who wished to protest to know which protest they could join and which they could not.

"The condition clearly failed to distinguish between assemblies and protesters participating in assemblies."

Ms Kaufmann told the court the Autumn Uprising was "intended to encourage multiple assemblies, by multiple groups, in multiple locations on multiple dates".

Those bringing the action include Stroud MP David Drew, Green Party politicians Baroness Jenny Jones and Caroline Lucas MP, Labour MP Clive Lewis and campaigner and journalist George Monbiot - who was arrested after the ban came into force.

David Drew said: " “I am supporting the right of Stroud constituents to be able to protest freely on the most important issue of our time.”

And in a statement issued ahead of the hearing, Caroline Lucas said: "The police use of a Section 14 order to ban all Extinction Rebellion protests across the whole of London was a huge over-reach of police powers.

"This power is there to help the police manage protests, not shut them down altogether.

"Extinction Rebellion are carrying a message we all need to hear. They won't be silenced by a police crackdown, nor should they be in a free democratic society."

The Met contends the ban, which is no longer in place, was lawful and was the only way of tackling the disruption caused by XR.

Lawyers for the force said it was "clear and undeniable" that XR regarded the Autumn Uprising as a single protest and that it was an "established tactic" of the group to "move around and change locations to frustrate law enforcement".

They said that, when the ban was imposed, it was not possible for the police to keep the disruption caused by XR to an "acceptable minimum", and indications were it would "continue and evolve in worrying ways".

In documents submitted to the court on behalf of the Met, barrister George Thomas said: "This is not a passing inconvenience. It is not the price to be paid in a democratic society that embraces the freedoms of expression and assembly.

"It is very serious disruption that has the potential to impact on public safety... and a direct, adverse impact on huge numbers of residents, visitors or workers in central London.

"These people also have rights, that are to be balanced against the rights of the protesters."

Mr Thomas said the costs of policing the Autumn Uprising were in excess of £20 million, adding: "Again this is not the price to be paid for facilitating lawful protest.

"The great majority of this has been incurred entirely unnecessarily, as a result of the need to respond to deliberate unlawful action by XR."

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 XR protest action to Trafalgar Square, but following "continued breaches" of the order officers moved in to clear the area.

The force said 1,832 people were arrested during the protests, and more than 150 were charged with offences.

XR's stated tactics are to cause "maximum disruption" and to overwhelm the capacity in police custody, including by refusing bail after being arrested.

Lord Justice Dingemans and Mr Justice Chamberlain are expected to give their ruling on the case at a later date.