SCOTTISH Power is to cut domestic gas prices by 4.8 per cent, the Big Six energy supplier announced today.

It said the cut will see the average annual gas bill on a standard tariff reduced by £33. It comes a day after a five per cent cut was announced by British Gas.

Energy firms have been under pressure from politicians and regulators to pass on the fall in wholesale gas prices to consumers. E.ON last week cut gas prices by 3.5 per cent.

The latest announcement will affect 1.1 million customers who are on standard or variable rates but not those on fixed tariffs.

The firm, owned by Spain's Iberdrola, also announced a new fixed-price deal which it said was one of the most competitive in the marketplace with an average dual-fuel bill of £930.

The gas price cut means that half of the Big Six firms that dominate household gas and energy supply in the UK have now reduced tariffs this month following sharp falls in the cost of energy on the wholesale market.

It will pile pressure on rivals SSE, npower and EDF to do the same.

Neil Clitheroe, Scottish Power's head of retail and generation, said: "Today's decision has been made to benefit our customers and keep our prices competitive.

"We will continue to keep our prices under review. Our pricing reflects all of the costs that contribute to a customer's bill.

"The wholesale price of energy accounts for half of a customer's gas bill, but non-energy costs such as transmission and distribution networks and environmental and social obligations remain unaffected by any wholesale energy price movements."

Customers already on fixed tariffs can move between tariffs at any time without paying exit fees, he added.