Police have made 71 arrests as climate change protesters caused fresh disruption on the M25, blocking roundabouts and the motorway itself.
For the second time in three days, Insulate Britain activists halted traffic on three sections of the road.
Long delays were reported at junctions 1a and 1b in Dartford, Kent; eight in Reigate and nine in Leatherhead, Surrey; and 23 in South Mimms, Hertfordshire.
Business Secretary Kwasi Kwarteng said the action was putting lives at risk.
He tweeted: “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.
“Not to mention the resulting traffic delays will only add to vehicle emissions.”
Demonstrators sat on the UK’s busiest highway as part of a campaign for government action on home insulation, while stranded motorists beeped their horns.
Angry drivers were seen in social media videos arguing with the activists.
The protest was reported shortly after 08:00 BST on Wednesday, with a number of protesters from Insulate Britain at junctions eight and ten.
It said 32 people had been arrested and that it was still on the scene, but the activists had been cleared from both junctions by 10:15 a.m. BST.
The force also stated that it was dealing with a four-vehicle collision on the anti-clockwise carriageway at junction nine, which resulted in the road being closed while emergency services responded.
The force stated that it was “too early in the investigation” to determine whether the crash was related to the protests.
Hertfordshire Police said officers were called to a protest near junction one of the A1M southbound / junction 23 of the M25 at South Mimms at 08:00 BST and detained 18 people.
It claimed to have arrived on the scene within minutes and attempted to engage with the protesters while adhering to “clear, national standards” and balancing “the rights of people to protest with the rights of those affected.”
“However, protesters ignored officers’ repeated requests to move to a safer and less disruptive location, and alleged that they had glued themselves to the tarmac, making it clear that their aim was to cause as much disruption as possible,” Supt Adam Willmot said.
He expressed gratitude to the public for their “patience and understanding.”
Kent Police said they were called around 08:20 BST to a report of two groups of people obstructing the road near junctions 1a and 1b – for the Dartford Tunnel and Princes Road, respectively.
It claimed to have arrested 21 people, with some of the activists allegedly glueing their hands to the road surface.
Although the road has reopened, Highways England reports that there are still delays at the affected junctions.
The action follows a series of protests on Monday when five junctions were blocked and 77 arrests made by police.
On Wednesday, the group said Insulate Britain “are back”.
It said 89 of its members were taking part in the latest action.
In a tweet, it said: “You’re angry. So are we… But sitting in the road makes Boris Johnson sit up and take notice, so we’re staying, until 10 Downing Street #getonwiththejob.”
It added in a statement, “Proper jobs for hundreds of thousands of people to begin the first real step – to insulate all of this country’s homes – which gives us the greatest reduction in carbon emissions pound for pound.” It’s a no-brainer, but this government refuses to do anything about it.”
In response to the protests on Monday, a government spokeswoman stated: “People’s daily lives should not be disrupted, especially on busy highways where lives are endangered and traffic delays only add to vehicle emissions.
“We are investing £1.3 billion this year alone to help people install energy-saving measures, and our upcoming Heat and Buildings Strategy will outline how we will decarbonize the nation’s homes in a fair, practical, and affordable manner.”
The AA’s Edmund King described it as “somewhat ironic” that during the previous blockade, a thermal insulation engineer was unable to get to work due to being stuck in traffic.
“While most people understand the need to take action on climate change,” he said, “these motorway blockade tactics are backfiring because they are alienating the working public trapped in this chaos and, as a result, pumping out more emissions.”
“These blockades affect essential deliveries, emergency services, and people missing hospital and business appointments.”
People have been using social media to express their views on the protest.
Elliot King from Norfolk tweeted: “Sitting in the road is ridiculous, dangerous and pointless. Stopping traffic and causing more emissions? Genius.”Meanwhile, Edward Lamb thanked the protesters and said it was “sad that this is what it’s come to, but protest works and I’m glad there are people brave enough to do it at this scale”.