Drivers dragged climate protesters out of the road and threatened to run them over on the eastern outskirts of London as Insulate Britain staged roadblock protests for the 13th time.

There were tense scenes as about 40 members of the climate activist group blocked the M25 at junction 31 and the London Road A1090 near the Dartford Crossing, with stranded drivers shouting abuse and accelerating towards protesters.

At the A1090, lorry drivers leaving nearby warehouses tried to use their vehicles to force demonstrators – who lay on the ground to prevent them from passing – out of the way.

One woman was almost run over by a driver who moved her car so far forward that the protester was beneath her bumper. Other drivers mounted kerbs and central reservations in order to evade the roadblock, while passersby dragged protesters to the side of the road to clear the junction.

One HGV driver said: “These lot, they don’t see the harshness of the reality. Why don’t they do something about racism? If they’re cold at home, just put on a jumper.” He said the protests were stopping him from doing the work he needed to feed his family.

Liam Norton, an Insulate Britain spokesperson, said: “In 10 years’ time when fuel crises are catastrophic, when the food has run out and when people are experiencing unsurvivable heatwaves, 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.”

It took almost an hour for police to arrive. Officers explained to furious motorists that they had been too busy clearing the junction 31 slip road to attend the second scene of protest.

Essex police tweeted: “Thirty-five people have now been arrested after we responded quickly to reports of roads blocked in Thurrock. Sixteen people were arrested at J31 of the M25 while 19 were arrested in Stonehouse Ln, Purfleet. All roads are now open.”

Insulate Britain is in its fifth week of disruptive protests, blocking busy roads and motorways in and around London. Wednesday morning’s M25 blockade was in defiance of a court injunction banning it from taking action on the capital’s orbital motorway.

It is calling for the government to agree to a programme to fit insulation in all Britain’s homes, starting with those of the poorest people.