Energy firm EDF today announced that gas and electricty prices would rise by 10.8 per cent from 7 December.
It follows in the footsteps of rivals Scottish Power, Centrica, npower and SSE, who have all raised prices in the last few weeks, although EDF's is the biggest so far.
The rise will add £2.35 a week to the average dual fuel energy bill.
Rising wholesale costs and extra costs relating to government energy efficiency schemes were blamed for the rise.
Audrey Gallacher, director of energy at Consumer Focus, said today: "Another price rise, hot of the heel of those we’ve already seen, will again feed into consumer concerns on pack behaviour and whether price changes are driven by real supply and demand issues.
"Energy companies obviously need to react to wholesale and other pricing pressures – but customers need to know the scale of changes is justified."
Price comparison website www.uSwitch.com said today that the recent wave of price hikes had forced up the price of the average yearly household energy bill from £1,259 to £1,334.