Dozens of environmental protesters have blocked traffic on Britain’s busiest motorway for the second time in three days.

Activists from Insulate Britain staged the demonstration at several sections of the M25 in London during the morning rush-hour on Wednesday, causing long delays.

The group, which is calling on the government to insulate the country’s social housing by 2025, said 89 of its members had blocked traffic for the second time this week.

Surrey police said there had been 25 arrests as of 10am, about two hours after the protests began.

The air ambulance and firefighters were called to the scene of a multi-vehicle collision at junction nine of the M25, near one of the demonstration sites.

The action came two days after 92 protesters were arrested for obstructing vehicles on some of the busiest routes in south-east England on Monday.

Motorists could be seen pleading with the activists to clear the road near junction 23, where two vital road networks meet.

In a statement, Insulate Britain said drivers were right to be angry but they would continue the direct action until the government pledged greater action on the climate emergency.

It said: “We will keep going until the government responds. Until it overcomes its complacency and cowardice and fulfils its first and most sacred duty: to protect the people of this country from harm.

“All we ask is that it makes a public statement that we can trust – that commits to the first step, to start the insulation of our homes. As soon as this happens we will leave the roads.”

The group previously said its demands were delivered by hand to 10 Downing Street on 21 August 2021 but so far the government had not responded.

Some of the activists involved in Wednesday’s protest were the same people arrested after Monday’s action, LBC reported.

Footage showed protesters in hi-vis jackets sat on the motorway with signs saying “sorry for the disruption” and “please turn off your engines”, while some motorists shouted abuse at them.

One driver told reporters she was on the way to collect her grandchild because her daughter was in labour, while another shouted that the protesters “should be shot”.

In a demonstration by the same group on Monday, five junctions of the M25 were blocked, leading to tens of thousands of drivers being stuck in huge queues of traffic.