The RAC declared the days of sub £1 a litre petrol a "distant memory" as it said prices rose for the third consecutive month in May.
The average unleaded pump price rose 2p to 110.59p a litre, while the average diesel forecourt price jumped 2.2p to 110.7p. Average supermarket prices for petrol and diesel increased by two per cent to 107.93p and 107.6p respectively.
"Motorists will be disappointed to see pump prices going up again having enjoyed filling up their vehicles with petrol and diesel for under £1 a litre at the start of the year. The sub-£1 litre is now sadly starting to seem like a distant memory."
Supermarkets cut petrol prices to below £1 a litre in the run up to Christmas, passing on gains from oil prices languishing around seven-year lows. But the black stuff has since recovered from below $28 per barrel in January to around $50 recently.
The RAC expects oil prices, and thus petrol prices, to stay at this level for some time. It cited rising demand in the US, as well as production outages in countries such as Nigeria and Libya and a passive Opec.
"Much depends on the physical price of oil not rising any further. The oil price teetered around the $50 mark for the last few days of May having risen due to the extra demand for the start of the US summer driving season, but it has yet to go higher," Williams added.
"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 Opec 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."