Analysts are predicting that the price of a litre of petrol will dip below 1 later this month, following a sharp fall in the value of crude oil.
The wholesale cost of crude has now dropped to $82 a barrel, its lowest level for 12 months.
Crude oil price fluctuations usually take between six and eight weeks to reach the forecourt, and affect both petrol and diesel costs.
Ray Holloway, director of the Petrol Retailers Association, said: 'If current trends continue, it is possible we could hit 1 a litre in some areas in October.'
The average price for a litre of petrol is currently around 109p and diesel about 120p.