British Gas parent Centrica has come under public and political fire after it revealed it made nearly £50 per household last year just months after hiking customer bills.
A £606 million profit haul at British Gas residential was slammed as "staggering" amid calls for the firm to use some of the cash towards reducing energy bills for its 8.4 million customers.
The 11% rise in profits came after last year's colder-than-normal weather saw gas use leap 12%, with British Gas making £49 on each average annual dual fuel bill of £1,188.
Its results have raised questions once more over the fairness of energy bill increases after British Gas raised tariffs by 6% at the end of last year. Centrica also confirmed that British Gas boss Phil Bentley is quitting at the end of June - and will leave with a combined share, salary and pension package worth around £10 million.
Trade union Unite said the energy regulator should be given more power to ensure utility providers "behave fairly". Len McCluskey, Unite general secretary, said: "British Gas' owner Centrica is making £50 per household in this country - that is staggering. These profits will anger a growing number of families who are struggling to pay the bills."
Underlying earnings at the wider Centrica group jumped 14% to £2.7 billion, but Centrica said it paid more than £1 billion in tax and invested £2.7 billion in 2012.
Chief executive Sam Laidlaw insisted the company needed to make a "fair and reasonable return so that we can continue to make our contribution to society and to invest".
Centrica stressed that British Gas contributes a fifth of total group profits, with 2012 results largely driven by a 20% rise in profits at its upstream gas and oil exploration business to £1.2 billion.
Consumer Focus called for greater transparency between profits and prices earlier this month after utility giant EDF revealed a £1.7 billion earnings haul just two months after raising bills for 3.7 million British households.
Shadow energy and climate change secretary Caroline Flint said it was time for a "complete overhaul of our energy market".