UK Transport Secretary Justine Greening called for a code of practice to be introduced to allow consumers to monitor daily petrol or diesel prices, saying legislation would be enacted if the industry did not act.
Her stance was welcomed by the Automobile Association, and Labour. However the FairFuelUK lobby group accused Ms Greening of attempting to deflect attention from the high rates of fuel duty imposed by the Government.
Ms Greening said: "For fuel companies not to pass on cuts in the wholesale price of fuel is not fair and not acceptable. There should be more transparency."
Claims that pump prices do not reflect global oil prices have been privately rejected by UK refineries who say delays in passing on savings are down to retailers getting rid of oil stock which was purchased at a higher price.
AA president Edmund King welcomed Ms Greening's remarks. He said: "Over the past seven years we have asked governments to act against the blurred world of UK pump prices, which every driver knows shoot up like a rocket and fall like a feather."
But national spokesman for campaign group FairFuelUK,Quentin Willson, said: "It's a bit rich for ministers to try and deflect the issue of pump prices to the oil companies and retailers."