The energy industry has accused ministers of underestimating the impact on households of its Energy Company Obligation (ECO) rules.
They will force companies to provide energy efficiency technology and home improvements to low-income households and others considered to be at risk of fuel poverty.
The scheme, due to start next year, will oblige firms to fund expensive modifications including cavity wall insulation.
Energy firms say ministers have understated the costs of the work, which will be recouped from other customers.
Energy UK, which represents the industry, is expected to publish a report by independent economic consultants suggesting the scheme will add as much as £50 to the average household bill.
That contradicts assurances from the Department for Energy and Climate Change, which is insisting that the changes will not mean additional costs for consumers.
Fairly obvious really. Insist that someone pays for something, that’s going to have an effect on bills to the consumer, isn’t it? For there isn’t that free money tree. The costs of something have to come from somewhere.