British Gas has come under pressure to cutcustomer bills after it revealed an 80% increase in profits, caused partly by last year’s price rises.

British Gas said freezing winter weather also helped to boost its January to June profit to £299million from £166million.

Critics would like to see the energy companyto share its good fortune by cutting bills for its 15.5 million customers who are still paying substantially more for gas and electricity than they were in January 2008.

Liberal Democrat spokesman Simon Hughes said energy firms had a duty to give their customers a fair deal and called on all the main suppliers to bring down their prices.

“Millions of people will be angry that they have to pay such high fuel bills when their energy supplier is making such whopping profits,” he warned.

British Gas emphasised that its residential arm’s January to June profits were up 80% on the same period of 2008 when profits were very low. It says that it has cut household gas prices by 10% in February and its electricity by 10% in May which together reduced off its average dual-fuel customer’s annual bill by £132 .

But those reductions have failed to reverse increases last year which together ramped up its gas prices by an average of 55 per cent and its electricity prices by 25 per cent. Managing director Phil Bentley said it was likely bills would come down in future but ruled out any imminent reductions.

“Yes, I can see prices coming down but we are investing heavily and we do expect to make a return,” he said. “It would be misleading to suggest prices are about to fall because the gas we are burning today is expensive gas we bought last year.”

Mr Bentley stressed British Gas had to strike a balance between keeping customers happy while still creating jobs and ploughing money into creating new power plants and green energy.