Despite a price war on supermarket forecourts in June, fuel prices failed to drop by a significant amount, a report has found.
The AA Fuel Price report revealed that although a price between the big supermarket chains cut petrol price by 2.5p a litre, the average price fell just 0.5p a litre in June, to 135.6p.
The cost of diesel fell 0.1p last month, with the average price now 139.7p.
The AA said recent speculation on the price of oil pushed fuel costs back up after the supermarkets lowered the prices of petrol and diesel.
The news comes as BP announced profits of 3.2 billion in the three months to the end of June.
Keep the costs of motoring down
Use our guides to keep your fuel bills as low as possible.