Average petrol and diesel prices both rose by 3p per litre in July, new figures show.
The average cost of a litre of petrol increased from £1.11 to £1.14 while diesel was hiked from £1.15 to £1.18, according to RAC Fuel Watch data.
That added nearly £2 to the cost of filling up a typical 55-litre family car.
The RAC believes retailers should be cutting forecourt prices by a few pence per litre within the next fortnight as the wholesale cost of fuel fell by 2p per litre for petrol and a fraction of a penny per litre for diesel last month.
The organisation’s fuel spokesman Simon Williams said: “July was another bad month for drivers with a 3p-a-litre rise in the price of fuel.
“This means petrol’s 7p a litre more expensive than it was at the end of May and diesel is 6p more, something drivers will no doubt have noticed as each complete fill-up is costing almost £2 more.
“The higher prices at the pump have been driven by the cost of oil increasing steadily to around 42 US dollars a barrel from a low of 13.21 US dollars in April.
“But drivers may well be given some respite as oil producers are planning on ramping up production despite the risk of renewed lockdowns around the world.
“This could easily lead to supply outstripping demand and therefore a reduction on the forecourts of the UK.
“There is some scope for retailers to already be reducing their prices. If they play fair with drivers we ought to see 2p a litre come off the price of unleaded and nearer 4p come off diesel.”