It has also offered to refund double the difference in pump price if a customer fills up at a Jet station and then sees petrol or diesel cheaper elsewhere on the same day. The initiative mirrors Esso's Price Watch campaign, which also offers assurance that Esso will match the cheapest fuel prices within two miles of its filling stations.

Esso insisted, however, that a new price war was not in the offing, and the Save Group, has forecast the end of cut-throat pump pricing and the start of a sustained period of growth for Britain's largest independent petrol retailer.

The director general of fair trading is reviewing the wholesale and retail petrol market in the UK and it is understood the findings are expected to be published shortly.