Angry motorists covered Insulate Britain protestors in ink today as they returned to London's roads during rush hour..
Activists were seen with blue on their clothes and faces as they started blocking the A40 and M25.
Insulate Britain has blocked two sections of major roads into London after warning its "non-violent civil resistance" would continue on Wednesday.
The road-blocking climate group obstructed the A40 in west London and a roundabout in Dartford in the east of the capital to urge the Government to better insulate homes.
Some protesters glued themselves to the ground - or each other, police said.
Retired doctor Christian, 77, told the Daily Mail : "It wasn't painful, it didn't hurt - it was unpleasant, but just sad, the whole thing's sad, it's sad that we have to do this.
"I hate doing it, I'm a retired doctor, I've spent my whole life trying to help people, and I'm reduced to having to do this because the Government won't address the problem adequately, basically. Terribly worried."
One member said she was prepared to lose her home and go to jail for the cause.
Suzie, 47, from Cambridge, who works in childcare, said: "If going to prison and losing my home is what it takes to get the Government to do the right thing and cut our carbon emissions then it's a price worth paying.
"I can't be a bystander while this Government betrays the public, our children and future generations by failing to defend our country from the climate crisis.
"Insulating Britain's leaky homes has to come first. It will cut out a huge chunk of our carbon emissions, help families struggling with their energy bills and end fuel poverty.
"It's such a basic first step that you have to wonder why the Government refuses to act. Don't they care?"
A Metropolitan Police spokesman said: "The Met is aware of Insulate Britain activists blocking the road at the A40 junction with Gypsy Lane in North Acton.
"Officers were promptly on the scene. Traffic has had to be diverted for the safety of all. We'll share updates soon."
Kent Police said in a statement this morning: "Fourteen people have been arrested after traffic on the A206 at Crossways Boulevard, Greenhithe, was obstructed in both directions.
"At around 8.05am on Wednesday 27 October 2021, Kent Police received a report that a group of protestors had gathered at the location and some of those involved had glued themselves to the road surface, or each other.
"Officers attended the scene within minutes and by 8.30am traffic was flowing in both directions.
"Each of the individuals was arrested on suspicion of obstructing a highway and conspiracy to commit public nuisance. They remain in custody as enquiries continue.
"Motorists are advised to expect delays and to use an alternative route if possible."