British Gas owner Centrica has swelled its profits to £356 million as its residential energy arm benefited from the past year's bitter winter.
Unite general secretary Len McCluskey said: Swelling profits are nothing to celebrate when fuel poverty is a very real concern.
"These profits will anger a growing number of families who are struggling to pay the bills, made worse when the fuel companies hiked their charges last year. Fuel bills run to around £1,500 per year - that is misery-inducing for most people.
"There should be a commitment from British Gas and the other fuel providers, all of whom have done very well out of the British people, to cut prices for customers this coming winter.
"Almost half of our members say heating bills are their biggest worry - there needs to be more action from the energy companies and the government. In the seventh wealthiest nation on the planet, people should not be forced into a choice of whether they heat or eat.
"The current model for Britain's energy needs is not working for the people of this country. Regulation should do more to ensure customers are not ripped off.
"Britain needs bold action to make our energy sector fit for purpose."
Contact Ciaran Naidoo on 07768 931 315
- Unite is Britain and Ireland 's largest trade union with 1.4 million members working across all sectors of the economy. The general secretary is Len McCluskey.