Fuel prices continued their rollercoaster ride in July with an increase of around 1p a litre for both petrol and diesel, new RAC Fuel Watch data shows.

Although average fuel prices had fallen by around 2p a litre in June following one of the worst petrol price rises in May 2018, they began to rise again last month. A litre of unleaded increased by 1.08p (127.72p to 128.8p) in July and diesel was up by 1.03p (130.82p to 131.85p)

The supermarkets increased their prices the most in July, largely cancelling out the price cuts that they had levied just a few weeks earlier. The price of an average litre of supermarket unleaded was up 1.64p to 125.34p, while diesel was up 1.62p to 128.88p. Motorway service areas, which tend to charge to the most for fuel, increased the price of a litre of petrol by 1.19p to 146.09p, but left diesel almost unchanged at 148.14p.

RAC spokesperson Rod Dennis said the volatility of the price of a barrel of oil, and in turn wholesale fuel prices, made it difficult to determine where prices might go next.