London's police warned on Friday that protests by environmental activists planned for the next two weeks will cause disruption across the capital and will distract officers from dealing with crime.
Extinction Rebellion, which caused days of traffic chaos in London two years ago, said it will target the capital's financial district in disruptive protests which are due to start on Monday.
The group accuses financial firms of helping to fuel climate change and it brought much of central London to a standstill during 11 days of action in 2019.
Those protests brought its cause to the fore and also provoked criticism from some politicians who said police had been too tolerant.
Ahead of next week's protests, London's police force said it would have to divert resources from other activities and some investigations might slow as a result.
"Every police officer committed to a large demonstration is a police officer abstracted away from their local borough and community," said Matt Twist, deputy assistant commissioner of the Metropolitan Police.
Extinction Rebellion's planned "Impossible Rebellion" protests - which come ahead of talks on climate change involving world leaders in Scotland in November - will include site occupations and marches through London's financial district.
The group said they would not be giving police specific information about their plans.
"We've made it quite clear that we've notified the police about what we're doing, that we've got a rebellion made up of separate actions," Paul Stephens, a former police officer and Extinction Rebellion activist, told reporters. "We're not telling them details."
Extinction Rebellion is demanding an emergency response to climate change from governments and a mass move away from polluting industries to avert the worst scenarios outlined by scientists.
(Reporting by Andrew MacAskill,; Editing by William Schomberg)
