Insulate Britain protesters are blocking part of the M4 on Friday.
The activists are currently at junction 3 near London. They area also blocking Junction 1 of the M1 at Brent Cross, north London as they stage their 10th day of protests in the past three weeks.
It comes just 24 hours after the protesters glued their hands to the M25 in Essex. Nine people were arrested on suspicion of obstructing a highway and were held in custody.
Read more: All the latest news from around the UK here.
Insulate Britain an offshoot of Extinction Rebellion, is calling on the government to insulate all UK homes by 2030 to cut carbon emissions.
The group has been repeatedly targeting the motorway in the last month despite an injunction being obtained by the government.
Tim Gough, an architect and academic, speaking to Radio 5 Live this week said: "Insulate Britain has a straightforward aim: that the government insulates all UK houses by 2030.
"This is an infrastructure investment project requiring Churchillian levels of political guts.
"The cost could be somewhere between £500bn and £1trillion pounds over eight years or £100bn per annum which is around 5% of GDP per year."
To get the latest email updates from WalesOnline straight to your inbox click here.
