Drivers faced chaos on Monday morning as campaigners blocked UK motorways in a protest over soaring fuel prices.
Protesters created a rolling blockade along the M4, heading towards the Prince of Wales bridge. Similar demonstrations were also due to take place in Yorkshire and Essex.
Police warned of “serious disruption throughout the day”, with motorists urged to stay at home where possible.
It comes amid growing discontent about the surging cost of petrol and diesel on petrol station forecourts, which has been driven higher by Russia’s war in Ukraine.
But motoring groups have complained that pump prices have remained high even after wholesale costs began to fall back.
Howard Cox, founder of the FairFuelUK Campaign, said: “These are not just demonstrations against the record excruciatingly high petrol and diesel prices that rise each and every day.
“They are also about the sickening chronic manipulation of pump prices and the complete lack of scrutiny by our out of touch Government, in allowing unchecked petrol and diesel profiteering to run rife.”
Devon and Cornwall Police tweeted: “We are aware of a go-slow protest having commenced at 7:10am from Exeter Services heading northbound.
“This is currently around a dozen vehicles in size and is being accompanied by police vehicles to ensure the safety of all road users.”
A Government spokesman said: “While we respect the right to protest, people’s day-to-day lives should not be disrupted, especially on busy motorways where lives are put at risk and resulting traffic delays will only add to fuel use.
“The new Public Order Bill will make it a criminal offence to glue yourself to a dangerous motorway, which sees police spending hours trying to safely remove people.”
