Energy firm EDF sparked gloom for millions more households yesterday after becoming the second supplier this year to announce inflation-busting gas and electricity price rises.
The French-owned company, which has 5.5 million UK customers, said it was upping gas prices by 12.9 per cent and electricity by 7.9 per cent from Friday due to "soaring" wholesale energy costs.
Earlier this month rival npower announced prices hikes of 17.2 per cent for gas and 12.7 per cent for electricity in a move that hit more than four million households.
EDF's announcement will see the average annual cost for one of its dual fuel customers rise about £100 to £1,007, and prompted anger from consumer groups.
It also led to fears that Britain's biggest energy supplier, British Gas, could reveal price rises as soon as tomorrow. The firm said any announcement would be made to the stock market.
Experts had been widely expecting rises from the UK's other main energy suppliers after npower's announcement on January 4 - which also took its average annual dual fuel bills to more than £1,000.
EDF's increases come just over six months after the firm cut gas and electricity prices by more than 10 per cent for customers as wholesale energy prices fell.
It also happened on the day Chancellor Alistair Darling was due to meet energy regulator Ofgem to discuss the energy market.
Energy consumer group energywatch said it was disappointed EDF Energy had moved so quickly to pass costs on to its customers.
Chief executive Allan Asher also renewed his call to refer the "big six" suppliers - British Gas, E.ON, Scottish & Southern Energy, npower, EDF and Scottish Power - to the Competition Commission.
He said: "The underlying causes of spiralling consumer prices are a wholesale market that punishes British consumers and a supply market that seems unconstrained by a competitive market from passing these costs on to consumers.
"The Chancellor's next call should be to the Competition Commission for a second opinion on Ofgem's assertion that all is well with the energy market in the UK."
EDF, which provides power through electricity distribution networks in London, the South East and East of England, blamed the rises on the doubling of wholesale energy prices over the past year and rising distribution costs.
EDF said wholesale gas prices had risen 117 per cent since February last year, with electricity up 90 per cent over the same time.
The cost of transporting and metering energy from power stations to homes had also gone up £4 per annum for electricity and £32 a year for gas users, the provider said.
EDF said the Government's Carbon Emissions Reduction Target, which sets out new targets for cutting carbon dioxide emissions during power production, would cost customers £100 million a year for the next three years.
Eva Eisenschimmel, chief operating officer of EDF Energy's customers branch, said: "We regret any decision to raise our prices. Despite soaring wholesale energy prices, higher distribution costs and increased environmental obligations, we have been able to substantially limit the impact on our customers."