EDF Energy has become the last of the big six suppliers in Britain to announce a tariff rise as it called an end to its winter price freeze on March 2.
Standard tariffs for electricity bills will rise by an average 7.5 per cent, while gas bills will increase by an average of 6.5 per cent.
An average annual standard dual fuel bill paid by direct debit will rise by 68 to 1,051, or an extra 1.31 a week, after the March 2 hike.
But EDF, which has 5.5 million customers in the UK, held its prices through the coldest December on record as part of its winter price freeze and claimed its customers benefited from some of the lowest prices in the market when it mattered most.
EDF had already increased electricity prices in October, although it is its first standard gas rise for residential customers since 2009.
The head of energy at watchdog Consumer Focus, Audrey Gallacher, said: "EDF Energy's customers will be hugely disappointed that the supplier has chosen to up its prices as soon as possible after its price freeze ends.
"Consumers will be further annoyed that this rise is even higher than that of most other suppliers, particularly given that the firm already increased electricity prices in October.
"This adds yet more fuel to the fire to the need for Ofgem's energy market review to clarify whether customers are paying a fair price for their energy."
EDF said its average customer uses more than half of their annual supply of gas between November and the end of February, so it has saved them money by holding prices down.
Martin Lawrence, managing director of energy sourcing and customer supply at EDF Energy, said: "We have delayed this increase until the end of a particularly difficult winter."