Petrol companies have been accused of profiteering after some prices on forecourts went up by 5p a litre in 48 hours, it has been reported.
The latest rises come despite threats of fuel protests by campaigners and planned strike action at a UK refinery.
A planned 2p increase in fuel duty is planned for October but campaigners have promised demonstrations across the country to create as much havoc as possible.
The cost of filling up an average family car has now risen by £8 in one year from £46.63 to £54.37, according to the AA.
Retailers claim that the rises are due to soaring prices of crude oil and campaigners have called on the Government to use fuel duty to soften the blow.
However some groups claim that fuel companies are simply putting up prices in anticipation of a scramble of drivers trying to fill up before the weekend.
The two-day strike is being staged by workers at a major oil refinery in Scotland. It is understood that 1,200 workers at the Ineos refinery will walk out on Sunday to protest over pensions.
Brendan McLoughlin, of the cost comparison website PetrolPrices.com, said some garages appeared to be raising prices because they knew drivers will be desperate to fill up.
‘Drivers should compare prices to make sure they don’t fall victim to profiteering,’ he said.
‘Prices are likely to increase further if the dispute is not resolved, so drivers need to make sure they are not getting ripped off.’
The Petrol Retailers' Association has denied 'profiteering', either by garages or by oil firms, saying prices are rising due to 'market conditions'.
A spokesman told PistonHeads : 'Prices have been going up due to market conditions partly due to increased demand coming into the summer months.'