Energy firms face price cut laws

Prices charged by all the major suppliers have risen in 2008

The government is ready to change the law to force energy companies to pass on falls in oil and gas prices, Commons leader Harriet Harman has told MPs.

Ms Harman made the comment as she was standing in for Gordon Brown at prime minister's questions.

The cost of wholesale gas is linked to the price of oil, which has slumped in recent weeks.

Some of the "big six" suppliers have already suggested prices could fall early in the new year.

Householders faced two price increases for gas and electricity bills during 2008, with the average dual fuel bill going up by more than