Police officers are looking to update the offence of “public nuisance” for the 21st century to ensure they have the necessary powers to tackle protest groups such as Extinction Rebellion, the Metropolitan police commissioner has said.

Cressida Dick told the London assembly she had been holding discussions with the Home Office to toughen up powers and legislation so police could clamp down on protests that aimed to “bring policing to its knees”.

Dick said the force wanted public nuisance to be made a statutory offence, rather than a common law offence, which would provide greater clarity for officers seeking to prosecute protesters and could give them greater powers.

The comments come as police forces face increased scrutiny over their handling of Extinction Rebellion after the Guardian revealed counter-terrorism policing had produced documents featuring the group and other non-violent organisations.

About 3,000 protesters were arrested across the two major periods of action staged by Extinction Rebellion in April and October last year. The group is calling for greater action from government and the public in tackling the climate emergency.

The common law offence of public nuisance, which was typically used for “obstructing the highway”, has all but disappeared and been replaced by specific criminal offences under different legislation.

There could be a political advantage to writing the offence into statute, as it would allow politicians to send a message to the public that they support or reject such a move.

Dick told the assembly: “Ever since the first large-scale Extinction Rebellion protest in April last year I have been talking publicly and with the government about the potential for change to powers and to legislation that would enable the police to deal better with protests in general given that the act that we work to – thePublic Order Act – is now very old, [dating to] 1986.

“But specifically to deal with protests where people are not primarily violent or seriously disorderly but, as in this instance, had an avowed intent to bring policing to its knees and the city to a halt and were prepared to use the methods we all know they did to do that.”

Dick repeated previous calls for a review of the act, as well as a lowering of the threshold before which conditions can be imposed on protests or assemblies.

“There is a phrase which is we need to be satisfied that ‘serious’ disorder, damage to property or serious disruption to the life of the community [has taken place],” she said. “That’s not further defined. But it seems in law, a high threshold. We think that could come down.

“Obviously we need to balance people’s rights, those who wish to protest reasonably and those who wish to go about their business. We completely want to do that and understand that’s required.”