(Updates with latest from police)
LONDON, Sept 15 (Reuters) - Environmental campaigners blocked parts of the M25 London orbital motorway on Wednesday, causing major disruption to some rush hour traffic around the British capital in their second such protest this week.
Insulate Britain, which is demanding that the British government gives a commitment to help provide insulation for 29 million homes, said more than 80 members of the group had blocked a number of junctions to the motorway, one of the busiest in Britain, as well as part of the carriageway itself.
Police, who have faced some criticism over their response, said they were had so far arrested 15 people. Insulate Britain said in a statement it would keep going until the government responds.
"In the meantime they can arrest us, they can put us in prison, we know who we are and what we have to do," it said.
Dozens of protesters were arrested by police on Monday when activists staged a similar protest at various points around the 117-mile motorway, causing hours of tailbacks and provoking fury from many motorists.
Some said how they had been unable to get to important health appointments while others said hospital staff had been unable to get to work.
"My son is autistic and started a new school this week which involves M25 travel. He is now calling me from the taxi having a meltdown because he cannot get to school because of your actions," Twitter user Liz Kelly wrote in response to a message posted by Insulate Britain about Wednesday's protest.
Surrey Police said diversions had been set up at two locations where protesters from Insulate Britain and Extinction Rebellion had gathered.
"We would advise motorists to avoid the area if possible," Surrey Police said.
Insulate Britain was unrepentant about the chaos it had caused.
"The people in cars are angry, they are outraged, they are disgusted. Rightly. What a thing to do. What stupidity. What idiots," it said. "So why are we doing it? Because we are angry, because we are outraged, because we feel disgust beyond words." (Reporting by Michael Holden; editing by Sarah Young)
Our Standards: The Thomson Reuters Trust Principles.