E.ON has announced an average 3.7% rise in energy bills which will come into effect on January 18th.
The E.ON rise is narrowly behind EDF, which is pushing prices up by 3.9% on 3rd January.
E.ON's dual-fuel customers will pay 3.7% more (around £48 a year), electricity-only customers will pay 3.7% more (£20 a year) and gas-only customers will see their bills go up by 4.6% (£37).
The Government confirmed on Monday that changes would be made to remove some social and environmental levies which would in turn reduce household energy bills by around £50 a year until 2015.
E.ON's rise has taken this into account. It said that without the reduced levies its price increase for dual fuel customers would have been £30 more, at £78 a year. EDF was also able to take the reduced levies into account when announcing its price increase, having acted later than other major suppliers.
British Gas has confirmed it will cut its prices to account for the changes, but Scottish and Southern Power (SSE), npower and Scottish Power are yet to announce similar plans.
Tony Cocker, Chief Executive for E.ON, said: "We have moved quickly to pass on the benefits of changes announced by the Government at the beginning of this week.
"Whilst there can be no guarantees, the likelihood of further price rises over the next 18 months caused by an increase in the cost of social and environmental obligations has receded due to the recent action taken by the Government."
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Energy price rises
In the past few months all of the other Big Six energy companies have announced rises. Scottish and Southern Energy (SSE) was the first followed by British Gas, npower, Scottish Power and EDF.
Here's a rundown of all the Big Six price rises so far and when they kick in.
Date of increase
Scottish and Southern Energy
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