Unleaded petrol was on sale in Bristol for less than £1 a litre last weekend as the US warehouse club giant Costco opened its latest filling station at its branch in Avonmouth.

When it opened unleaded petrol was priced at 99.9ppl, with diesel at 102.9ppl, although on Monday prices were raised to 100.9ppl and 104.9ppl respectively.

Costco Wholesale is only open to members, and the forecourt in Bristol is its third after making its UK debut at Liverpool in June 2014, followed by its Oldham branch in August this year.

A spokesman said the company, which has 27 sites in UK, plans to open more filling stations in Sheffield, Thurrock and Derby early next year.

The latest forecourt has 12 self service pumps which only accept debit cards or American Express cards. It will be open from 6am to 9.30pm on Monday to Friday, 6am to 7pm on Saturdays, and 7am to 6pm on Sundays.

Simon Williams, fuel spokesman for the RAC, told the Bristol Post: “Costco members in Bristol probably can’t believe their luck as they are able to buy the cheapest petrol and diesel in the country.

“Just like the name suggests, it looks like they are selling their fuel at cost and not making any money on it to reward members.”