Two leading supermarkets have cut their petrol prices in a bid to keep hard-pressed motorists moving as this weekend's predicted cold snap looms.

Both Asda and Tesco have cut prices with Asda introducing a 2p per litre reduction, guaranteeing motorists petrol at a maximum of 129.7p per litre for unleaded and 137.7p per litre for diesel. Tesco have responded with cuts of up to 3p per litre on their forecourts.

The price reductions come as new research has found 87 per cent of all UK car-owning households are within five miles of a supermarket petrol station.This means roughly 15.5 million households will be able to fill up more cheaply this weekend.

In England, virtually all car-owning households (99.7 per cent) are within 15 miles of a petrol station owned or operated by Tesco, Asda, Sainsbury's or Morrisons.

Responding to news of the price cuts, RAC technical director David Bizley said: "Every penny off fuel makes a difference for motorists.

"The price of fuel is having a negative impact on families as they are cutting social and family journeys in an effort to save money.

"This will help make it a little more affordable for families to travel to spend time together this Christmas.''

Motorists will no doubt be hoping that the forecasted big freeze will go beyond the weather as a 3p-per-litre fuel duty increase is expected to be announced next Wednesday ready for the new year.