The figures for May reveal that the average unleaded pump price rose 2p a litre (1.92p) from 108.67p a litre to 110.59p, while diesel was up by 2.2p a litre from 108.49p to 110.70p.

Average supermarket prices of petrol and diesel increased by 2% – 1.85p a litre for petrol (106.08p to 107.93p) and 1.68p for diesel (105.91p to 107.59p).

Wholesale prices of both fuels have also gone up; petrol by 3.2p a litre and diesel by 4p a litre, predominantly as a result of the oil price continuing to rise. The spot price of oil rose 14% in May, adding $6 to a barrel (rising from $43.18 on 3 May to $49.26 on 31 May), and a barrel also reached its highest price since mid-October 2015 when it finished trading at $49.53 on Thursday 26 May.

RAC fuel spokesman Simon Williams said: “The sub-£1 litre is now sadly starting to seem like a distant memory.

“Much depends on the physical price of oil not rising any further. The oil price teetered around the $50 a barrel mark for the last few days of May having risen due to the extra demand from the start of the US summer driving season, but it has yet to go higher. Fortunately, some of the refinery issues, which had led to lower than expected output, have been resolved and we now have increased crude production in the Middle East.

“And, with the Organisation of the Petroleum Exporting Countries deciding not to curtail production at its six-monthly meeting in Vienna on Thursday, there is good reason to expect the oil price will not go far above the current level for the time being, but predicting what will happen with oil is far from straightforward.”