The RAC has called for petrol retailers to cut the price of petrol to reflect a drop in wholesale costs.
Fuel prices have rocketed in line with oil costs in recent months, with both petrol and diesel hitting record highs in recent weeks.
But wholesale prices appear to have since gone down.
Its call for a drop in prices has come as a farmer from County Durham began a protest about the issue on the A1 motorway near Newcastle on Saturday morning.
What has the RAC said?
According to the RAC, average pump prices for petrol have risen by 3p per litre since the start of November, reaching 147.27p.
The motoring organisation said fuel retailers should “play fair with drivers” and reduce this price by 6p.
It said it believed the failure to pass on savings is costing motorists an additional £3.50 every time they fill up a typical 55-litre family petrol car.
RAC also called for diesel prices to come down by 4p from its current average of 150.66p per litre.
“In the last few days the wholesale price of petrol has fallen steeply, which means the biggest retailers are in a great position to cut prices and ease the burden being felt by drivers throughout the UK who are paying £80 for a full 55-litre tank,” said RAC fuel spokesperson Simon Williams.
“As the big four supermarkets are responsible for selling 45% of all the country’s fuel, they are constantly buying new supply so they’re able to pass on the savings to customers straightaway – unlike smaller retailers who tend only to buy in fuel once a fortnight.
“The longer they hold off doing the right thing, the more money they make on every litre they sell and the worse off drivers are.
“This seems very harsh on drivers considering how many are struggling financially because of the inflated cost of filling up.”
Mr Williams said research by the RAC had found 46% of drivers would have to cut other household spending as a result of the continuing rise in the price of fuel.
A1 fuel protest latest
The RAC’s calls come as farmer Andrew Spence began a protest on the A1 motorway around Newcastle to highlight the high price of diesel.
Mr Spence, 54, from Leadgate, County Durham, said he would lead a 5mph convoy of farm vehicles up and down the A1 from 11am.
In 2000, the farmer led a blockade of oil refineries with his Fuel Lobby group.
He has said he wants to see a “substantial” reduction in prices.
The protest is set to hit the A1, Gateshead and Newcastle city centre.
Mr Spence’s protest could impact events being held in Newcastle today, including the Premier League football match between Newcastle United and Brentford.