Speaking at a UK Environmental Law Association (UKELA) event just hours after the ruling yesterday, XR spokesperson Zion Lights welcomed the “really good news” but said XR would not advise its members with anything specific, saying they would make their own decisions.
The Metropolitan Police imposed the ban, which prevented two or more people from the group taking part in protests, under the Public Order Act.
However, judges have ruled that the police had no power to do this because the law did not cover "separate assemblies".
The police could now face claims for false imprisonment from "potentially hundreds" of protesters.
Lights said: “It was quite horrific being in Trafalgar square when the police were getting a bit more heavy-handed and dragging people away when they were still in their tents. It was heart-breaking when the police were chucking some of the artful structures [protestors had made] straight into landfill.”
Lights said the Met’s handling of last month’s protest had been surprising “because we actually have quite a good relationship with the police, including police liaisons and we communicate well with them during protests. So when the police officers told us that they had been ordered to prioritise policing us over crime in the rest of the city, it was really shocking. They had told us we could stay in Trafalgar Square but they suddenly changed their minds without warning.”
Public Order Act 1986
She added: “There is a big question here. Who are the police serving and who are they protecting? Because this is a load of ordinary people that were not being treated fairly. The same thing can be said of the government. We tried to engage with them on the ground but Prime Minister Boris Johnson called us 'uncooperative crusties', which is quite a strange thing to call thousands of ordinary voters.”
During the court hearing, the force had argued that the ban was the only way to tackle widespread disruption.
The protests cost £24m to police and led to 1,828 arrests, with 165 people charged with offences, the Met says.
However, Lord Justice Dingemans, announcing the judgment, 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."
The Met has said it will "carefully consider" the ruling.