By Natalie Thomas
The cost of diesel is falling at supermarket pumps following drops in the wholesale prices of the fuel.
Morrisons was first to deliver the news that it would be cutting the price of diesel by up to 2p per litre. Following behind were Sainsbury's, Asda and Tesco.
However, motoring groups claimed the cost of fuel still depended on where people live, with large regional differences in what motorists pay.
According to the AA, the typical cost of diesel is 143.39p per litre, after it hit a top price of 146.38p earlier this year.
On average, petrol costs 137.75p per litre, in comparison with a 140.03p peak in March.
The AA said: "Although the reduction in the price of diesel is very welcome, the question is to what extent this is reflected in rural areas where it is essential for country business and activities.
"There is traditionally a springtime fall in the cost of diesel as the demand for heating oil, which comes from the same part of the oil barrel, drops off."
Mark Todd, petrol director at Morrisons, said the price reduction was because of "a drop in wholesale prices, combined with an improved exchange rate".
Consumer studies have been consistent in highlighting the effects of increasing pump prices on family budgets.
Big supermarket chains also reduced the cost of their diesel in the middle of March.
A fuel duty increase set for September was cancelled by the Chancellor of the Exchequer during his Budget speech on March 20.
Wholesale petrol prices are also dropping, the AA said, and the motoring expert added that it thinks this means "a 1p drop in the pump price is on the cards".
In America, the price of diesel has dropped for six weeks running, according to statistics from the US Energy Department.