Dozens of campaigners who are calling for a cut in fuel duty targeted the M4 in South Wales and Somerset, and stretches of the M5 from Devon to Bristol, on Monday.

Major highways in Devon, Shropshire, West Yorkshire, the York and Essex were also affected.

In a series of 30 miles (48 km) per hour rolling roadblocks, the protesters were able to bring disruption to road networks during the morning rush-hour.

The protests, which started at around 7am, are understood to have been organised via social media under the banner Fuel Price Stand Against Tax.

They come as the average price of petrol reached a new high of 191.5 ($A3.38) per litre on Sunday, while the average price of diesel was 199.0 p ($A3.52) per litre.

Police escorted the two blockades as they crossed the River Severn but prevented them from making the return journey.

At least eight motorists were arrested for public order offences and had their vehicles seized, according to eyewitnesses.

Meanwhile, Devon and Cornwall Police said a motorist in his 50s was arrested on the A38 for a public order offence after allegedly driving repeatedly at a "dangerously low speed".

The AA claimed that petrol wholesale costs ended last week 10p down on the record highs of early June.

The organisation's fuel price spokesman, Luke Bosdet, said: "It is an outrage, plain and simple, that the fuel trade could be slashing petrol prices as the nation heads towards the holiday season, but isn't."

Chancellor Rishi Sunak said he will carefully consider calls for a "more substantial" fuel duty decrease after the 5p-per-litre reduction implemented in March failed to halt price rises.

The government said that, while it understands that people are struggling with rising prices and have a right to protest, "people's day-to-day lives should not be disrupted" and warned that traffic delays "will only add to fuel use".

Australian Associated Press