After a brief reprieve the autumn energy price rises have continued, with EDF Energy announcing a 3.9% price hike.
The firm, the fifth of the big six to announce a climb in prices, said it is "holding back rising costs" including those from the government's environmental scheme in order to limit price rises for customers.
The increase will add £50.37* a year to average EDF customers' bills, its average standard variable price rising to £1,300.
The price hike will come into effect from 3 January, 2014.
The move comes as investors in the energy market threaten to pull out under the threat of changes to regulation.
"The company recognises that a price rise is especially unwelcome in the current economic climate, but believes that today's action to limit the growth of bills is an important step," said EDF in a media statement.
Gocompare.com's Jeremy Cryer said: "While EDF's price rise may only be half that of what four of its other 'big six' counterparts have so far inflicted on consumers, it is still a price increase, and people should see it as yet another reason to make sure they are on the best tariff for them.
"Many consumers have got the message, and have been moving to better tariffs in their droves. Energy switching has increased by 1,400%** since the first of the big six - SSE - announced its price rise, and most people clearly aren't waiting for Ed Miliband to sort things out for them, as three quarters** are opting for fixed tariffs that allow them to take control of their outgoings for two, three, or even four years.
"With energy prices seeming to rise relentlessly, people may feel like they're in something of a lose-lose situation and that they may as well stay put, but this is folly. At worst, shopping around will result in you finding the cheapest tariff for you, and at best it could actually result in a saving of £300 or more.***
"The only way to be sure that you're getting the best price is to compare your tariff against those offered by other providers, and often. In just a matter of minutes it's possible to compare all of the gas, electricity and dual-fuel tariffs available, and that's time well spent."
Fixed-price tariffs have the potential to be a great way to save money on energy, and it's surprisingly easy to switch.
In a statement, EDF Energy chief executive Vincent de Rivaz said: "The best way to help customers is for us to keep our prices as low as possible. I know that price rises are always unwelcome, but we have taken the first step to show what can be done if rising costs are tackled head-on.
"Energy firms, politicians and consumer groups need to be part of the solution and stand on the side of customers to give them energy at an affordable price. That means operating as efficiently as possible and designing the most cost-effective social and environmental programmes."
E.On is now the only one of the big six yet to raise their prices this autumn.
*Based on a medium user (3,300kWh of electricity and 16,500kWh of gas a year)
**According to Gocompare.com figures, 76% of people switching energy since 10 October, 2013, have opted for fixed tariffs
***Based on customers who switched energy supplier for both gas and electricity (dual fuel) using the Energylinx powered Gocompare.com platforms in the period 1 July-30 September, 2013. At least 10% of people who switched energy supplier for both gas and electricity with Gocompare.com saved £309.05