Environmental protesters have blocked a junction of the M25 in Hertfordshire as part of their campaign to improve home insulation.

Members of Insulate Britain blocked slip roads and the M25 carriageway itself in a number of locations and poured paint on to the roads which will require cleaning and lead to further disruption, the group said.

Images taken by the campaigners show people sitting on the ground on the roads holding signs saying “Insulate Britain”.

CCTV motorway traffic cameras of the M25 anticlockwise at J18, the Amersham and Watford turnoff, showed traffic piling up across the three lanes shortly before 8.40am on Monday.

Surrey Comet: Paint on a slip road at Junction 18 of the M25, near Rickmansworth (PA)Paint on a slip road at Junction 18 of the M25, near Rickmansworth (PA)

A statement from the group said: “Early this morning, Insulate Britain blocked the M25 for a fourth time.

“Actions will continue until the government makes a meaningful commitment to insulate all of Britain’s 29 million leaky homes by 2030, and all social housing by 2025.

“People blocked slip roads and the M25 carriageway itself in a number of locations. Once again, blue paint was poured onto the road, which will require cleaning, leading to further disruption.

“Many of those blocking the roads today have participated in all four actions to date.”

The group wrote to National Highways and the police to urge for speed limits to be reduced and to alert them to the action on Monday.

A spokesperson for Hertfordshire Constabulary told the PA news agency: “Police were called at 8.12am today (Monday 20 September) to reports of protestors near junction 18 (Chorleywood) of the M25.

“Police were also called at 8.15am to reports of protestors near junction 4 (Stanborough Interchange) of the A1M.

“Officers are at the scene and working to resolve the disruption as quickly as possible.”

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