“We can see no reason why motorway fuel should be so much more expensive. In fact, arguably it is much easier from a delivery point of view than it is getting fuel to urban filling stations. Questions need to be asked to find out what reasons motorway service operators have for charging such increased prices.

“Our research actually shows that almost a third of drivers would come off the motorway and add another 10 miles to their journey to find cheaper fuel.

“There is also a real concern that some motorists may decide to risk getting home with what they have left in the tank, rather than fill up at an expensive service station, and potentially run out of fuel. That presents a real danger, both to that driver and other road users.

“We’re calling for motorway fuel retailers to be more reasonable with their pricing. In fact, a quarter (24%) of the drivers we surveyed would accept paying 2p extra at motorway services, but not an extra 10p.”

The issue of giving motorists advance warning of motorway fuel prices – something the Government had pledged to address last year but as yet has not act – was also a concern.

Williams added:

“We feel it’s only fair that the motorist is able to make a choice about how much they want to pay for fuel before coming off at the exit and having to accept whatever they are presented with. It’s not like anybody has a choice about whether they put fuel in the car or not, but they should not have to experience this 21st century form of highway robbery.”