Police have arrested 71 climate protesters after they blocked parts of the M25, the motorway surrounding the British capital, causing huge traffic queues during rush hour on Wednesday.
Dozens of activists from Insulate Britain, which is demanding government action on home insulation, stopped traffic on three sections of Britain's busiest motorway shortly after 8 am (0700 GMT) on Wednesday - the second time in three days.
Demonstrators sat on the road while stranded motorists beeped their horns. Videos posted on social media showed angry drivers remonstrating with the activists.
Surrey Police said there had also been a crash, involving multiple vehicles, at Junction 9. It was "too early in the investigation" to know if the crash was linked to the protests, the force said.
Business Secretary Kwasi Kwarteng commented: "These actions are not only highly disruptive to those going to work and transporting vital goods, but are putting lives at risk on a busy motorway."
Automobile Association president Edmund King said: "Whilst most people understand the need to take action on climate change, these motorway blockade tactics are just backfiring as they are alienating the working public stuck in this chaos and subsequently pumping out more emissions."
He added: "Essential deliveries, emergency services, people missing hospital and business appointments are all hit by these blockades."
Surrey Police said it worked with the Metropolitan Police to deal with the protesters, making 32 arrests. Hertfordshire Police said it arrested 18 people.
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."