Around 40 members blocked the M25 at Junction 31 and the London Road A1090 near the Dartford Crossing at 8.30am on Wednesday.
Irate lorry drivers moved to yank the activists by their arms and legs out of the road before police could arrive.
This is the thirteenth time that Insulate Britain has caused travel chaos in a month.
The area near the Purfleet Freight Terminal is home to a number of business sites – and a route for freight.
The group were seen quickly donning high-vis jackets before walking out on the roundabout without a police officer in sight.
Drivers were left to attempt to drag the activists off the road by Purfleet Docks.
One activist then sneakily bumslides back onto the road as the furious driver’s back is turned.
One driver said: “Look you’ve made your point but you are going to gridlock the whole area. This is not going to help. “My business is on its knees. We have a massive haulage problem in the UK and this is a key point. “Look at my warehouse there – how am I going to insulate that?”
Another driver, filmed trying to drag the activists away, barks at the group: “Why aren’t you at work? Why are you just sitting there, please just move. You self-satisfied p***.”
A furious mother taking her 11-year-old son to school also demanded they move with one lorry driver complaining he missed a job interview because of the hour long delays.
Dr Diana Warner, who the group described as an Insulate Britain supporter, said: “Many people are going out of their way to thank us.
“Some come out of their cars to thank us, some are police officers involved with our arrests. To them, we bring hope – we haven’t yet given up. We are still pushing for life saving changes.
“It is a big step to move from thanking us to taking action. But if you make some move to help us, however small, you will be helping us to achieve change.”
Liam Norton from Insulate Britain said:“ In 10 years time when fuel crises are catastrophic, when the food has run out and when people are experiencing unsurvivable heat waves, what would you be wishing you had done now?
“We think you’ll be wishing you had sat on the road with Insulate Britain doing whatever it took to protect current and future generations. So come join us on the road.”
Responding to the incident, Essex Police said: “We are currently on scene and have made arrests following reports of people blocking the slip road of the M25 in Thurrock.
“We received reports of people on the road at Junction 31 shortly after 8.25am today.
“Officers were at the scene within five minutes and are currently working to resolve the situation quickly and safely. Arrests have been made.
“We know this will be frustrating for people caught up in traffic but we appreciate your patience and understanding.”