The Met Police spent £4m on protests between 13 September and 20 November, according to figures released to the PA news agency under a Freedom of Information request.
Forces spent more than £300,000 combined, with hertfordshire police £85k
Insulate Britain spokeswoman Tracey Mallaghan said the group would “much rather money was being spent on insulating homes and helping get people out of fuel poverty”.
They repeatedly blocked major roads between September and November, causing massive traffic disruption.
The Met said 6,651 of the force’s officers and staff were involved.