LONDON — The eco-protest group Extinction Rebellion won a bid against London's Metropolitan Police on Wednesday over the imposition of a city-wide ban against the group's series of demonstrations last month.

The high court ruled that the blanket ban police issued on Oct. 14 to 18 was unlawful, a decision protesters are celebrating.

"It is a victory," Tobias Garnett, human rights lawyer representing Extinction Rebellion, said outside the court as supporters cheered.

"This was an unlawful overreach of police powers and a disproportionate infringement on our rights to protest and we’re very glad that the court has agreed with our suspicion today," Garnett later told NBC News.

Extinction Rebellion, also known as XR, launched a series of protests on Oct. 7 worldwide — involving blocking roads and bridges and activists gluing themselves to buildings — that saw over 1,800 people in London alone.

London's Met police responded to the so-called Autumn Uprising with a blanket ban "in order to help us get London moving again," a spokesman said at the time.

The group uses non-violent civil disobedience, including intentionally being arrested, to draw attention to the ecological collapse being threatened by climate change. XR demands that governments “tell the truth” about climate change, ensure that net-zero emissions are achieved by 2025 and establish a citizens’ assembly to inform how the transition should happen.

More than 400 people were arrested while the ban had been in place, according to XR.

"Rather than wasting its time and money seeking to silence and criminalize those who are drawing its attention to the climate and ecological emergency, we call on the government to act now on the biggest threat to our planet," Garnett said in a statement.

Following the ruling, he added that those arrested during the ban could now sue police for wrongful imprisonment and XR's legal support team will be giving advice on an individual basis.

Met police called the court's verdict disappointing in a statement, defending the decision to implement the ban.

“After more than a week of serious disruption in London both to communities and across our partner agencies ... we firmly believed that the continuation of the situation was untenable," said Assistant Commissioner Nick Ephgrave.

At least £24 million ($31 million) was spent on policing the October protests, which required officers to work 12-hour shifts while drawing attention away from other priorities, police said.

The ban wasn't intended to block all protests but calm the specific series of events at the time, Ephgrave said. "It did in fact result in the reduction of the disruption."

The case highlights the challenges and limitations of policing widespread demonstrations within current British laws, Ephgrave added. Met police are reviewing the details of the ruling and will decide on its next steps.