Climate protesters have blocked parts of the M25 for the second time in three days.
Insulate Britain, which is demanding Government action on home insulation, stopped traffic at two sections of Britain's busiest motorway.
They targeted Junction 23 for South Mimms in Hertfordshire and the main carriageway from Junction 8 at Reigate to Junction 9 at Leatherhead, both in Surrey.
Demonstrators sat on the road, causing huge queues of traffic and at least 15 arrests have been made.
Videos posted on social media show angry drivers remonstrating with the activists.
Insulate Britain said 89 of its members took part in the action on Wednesday
It said in a statement: "We demand credible action now.
"Proper jobs for hundreds of thousands of people to start the first real step - to insulate all the homes of this country - which pound for pound gives us the biggest reduction in carbon emissions.
"It is a total no-brainer and yet this Government refuses to get on with the job. This is criminal negligence."
A demonstration by the same group on Monday saw five junctions of the M25 blocked, leading to tens of thousands of drivers being stuck in huge queues of traffic.
Dozens of people were arrested.
Surrey Police said in a statement: "A number of protesters from Insulate Britain and Extinction Rebellion are at the two locations and appropriate diversions are being set up with the help of partner agencies."
Crash on M25 amid protests
Surrey Police said officers are dealing with a crash involving four vehicles on the M25, amid climate protests on other parts of the motorway.
The force said 25 Insulate Britain and Extinction Rebellion activists had been arrested just after 10am on Wednesday.
Surrey Police said: "A total of 25 arrests have been made.
"We are also dealing with a road traffic collision at Junction 9 of the M25 involving four vehicles.
"Police, fire service and ambulances are currently on the scene."