The price of petrol at the pumps is rising again after weeks of falls.
A litre of petrol now costs 132.18p on average, with diesel at 137.26p, motoring giant the AA says.
Average petrol prices peaked at 142.48p a litre in mid-April and were as low as 130.81p at the beginning of July, before going up again.
But the AA says motorists could have been paying even less for fuel at the start of the month, had a fall in the wholesale price of petrol been fully passed on to consumers,
Now, wholesale prices have gone up again, with market speculation which inflated prices earlier this year re-emerging, it adds.
Price boost for London drivers
The AA adds Londoners appear to be enjoying an Olympic fuel price boost.
Prices in the capital are usually among the most expensive in the country but, at 132p for petrol and 137.2p for diesel, are now not only lower than the UK average but not far off prices in the Midlands and the north of England.
Across the UK, petrol is cheapest in Yorkshire and Humberside at 131.6p a litre and most expensive in Northern Ireland at 133.4p.
South east England is dearest for diesel at 137.8p a litre and is cheapest in Yorkshire and Humberside at 136.6p.
AA president Edmund King says: "It was inevitable pump prices would eventually rise again but, as has been the case so many times in recent years, the questions remain: should it be happening now and what is driving them up?
"Is it the fundamentals of supply and demand or speculation in the oil and wholesale fuel markets? Current evidence seems to suggest the latter."