EDF Energy have pledged to pass on savings to customers if the Government makes changes to the cost of social and environmental programmes.
It said the move comes in advance of a review of these schemes by the Government after Prime Minister David Cameron pledged to "roll back" green energy levies.
The statement read: "If the Government makes bigger changes to the costs of its social and environmental schemes than EDF Energy has anticipated, the company pledges to pass these savings onto customers.
"However, if changes to social and environmental programmes are less than anticipated, the company may have to review its standard variable prices again."
More top news
Former shadow foreign secretary Hilary Benn led calls by a series of senior Labour MPs urging colleagues to 'win' back the party.
A team of detectives and specialists is set to begin a painstaking excavation of the area where Ben is thought to have gone missing in 1991.
The foreign secretary's suggestion last week's bombing of an aid convoy might constitute a war crime prompted an angry response from Moscow.