Walmart-owned Asda as part of an exclusive three-day promotion has lowered the price of a litre of unleaded petrol by 4p to 99.7p (€1.4, $1.5). The cut coincides with the Black Friday weekend and will end at midnight on 29 November.

This is the first time since 2009 that fuel prices have fallen below £1. Petrol will be available at the reduced rate in the supermarket's 260 petrol stations across the UK.

Asda's move follows Morrisons, which earlier this week announced that petrol would be available at a discounted price of 98p a litre to customers who spend £40 in a participating store. This promotion also runs till 29 November.

Chancellor George Osborne in the recent Autumn Statement had announced that the freeze on fuel duty would continue to remain in place. Andy Clarke, Asda's president and chief executive, said: "The chancellor's freeze on fuel duty is what our customers were hoping for. We're adding a further boost by investing in a three-day fuel price drop meaning drivers can now benefit from fuel as low as 99.7p per litre in the crucial run-up to the festive period."

Crude prices in general have taken a hit in recent times following the China slowdown. RAC Fuel Watch spokesman Simon Williams said: "Due to the latest dip in the crude oil price we had predicted that the most price-competitive fuel retailers would soon be selling petrol for £1 so it is great to see that landmark price is now available across the country at the most expensive time of year."

Asda, which has a 7% share in UK's petrol market, said it would not participate in Black Friday this year due to "shopper fatigue" which it experienced last year. The supermarket witnessed chaos as customers fell over each other in an effort to buy discounted items.

Hence instead of providing steep discounts over one day, the retailer will run low prices on various products across most of November and December. Some of the deals include £10 bottles of champagne, half-price Barbie and Lego sets and an Oral B 2500 electric toothbrush at more than 50% discount at £29.97.