The Metropolitan Police have spent £7.7m policing 13 weeks of Just Stop Oil protests, the force has said.
Protestors mounted 515 protests since April and the cost of handling the disruption amounted to the equivalent of 23,500 officer shifts.
Actions included slow marches in busy London roads and disrupting major sporting events, and more than 270 people have been arrested.
It comes on top of the £7.5m officers spent policing Just Stop Oil (JSO) demonstrations between October and December last year.
Assistant commissioner Matt Twist told LBC the force was “resilient” but dealing with a “chronic” issue.
He said: “In terms of every single day, we’ve got over 150 officers who ordinarily would be policing in local communities, who are policing in and around other parts of London.
“And one of the challenges we have with Just Stop Oil is they don’t tell us where they’re going to protest, they don’t tell us when they’re going to take this action, they don’t engage, which means that we have to put more officers on it than we otherwise would do.”
Activists have disrupted events including The Open, Wimbledon, the Ashes, the Gallagher Premiership rugby final at Twickenham and the World Snooker Championship.
Chelsea Flower Show and the London Pride March also saw action taken, while protestors disrupted filming of the Channel 4 show The Last Leg, and sprayed orange paint on the Department of Energy Security and Net Zero building in central London.
A spokesperson for the mayor of London said: “The mayor supports the democratic right to protest, however, Sadiq has always been clear that protests must be carried out safely and lawfully and should not put Londoners or the capital’s recovery at risk.
“The extreme weather events London has experienced in recent years show how much more needs to be done to tackle the climate emergency, but protestors should consider whether their methods risk turning public opinion against a vitally important cause.
“The mayor supports the Met’s efforts to keep Londoners safe and keep our city moving.”