DRIVERS have been forced to pay nearly 5 more than necessary to fill up their cars.
Fuel firms have raked in nearly 500million in weeks by refusing to pass on price drops.
A study shows that since Christmas wholesale petrol and diesel costs have fallen nearly 14 per cent.
But at the same time, the average pump costs have increased by 2.2p for petrol and 3.4p for diesel.
The difference in diesel costs and forecourt prices was the biggest, with oil firms including BP, Shell and Texaco refusing to pass on 327million in savings.
It means that last month the average family with a diesel car paid nearly a fiver more for fuel. The companies also kept 147million from the difference in petrol costs and prices.
That totals 474million fleeced from drivers between December 23 and the end of January.
The FairFuel UK campaign said the research exposed the desperate need for an independent fuel pricing watchdog to ensure falling wholesale costs are passed on to drivers.
Before the election ministers said they were considering a proposal to create a new PumpWatch regulator.
FairFuel UK founder Howard Cox said: Characteristically, greedy fuel supply chain businesses have chosen to stuff their wallets at the expense of hard pressed drivers.
This is why Boriss government must implement an independent fuel pricing watchdog as a matter of urgency, to stop the habitual ripping off of motorists every time they fill up.