The utility said that the increase of 9.7% on electricity and 15% on gas is effective for the majority of existing customers from February 8, 2008, and is the direct result of rising wholesale costs, which have increased by over 60% since February 2007, when E.ON announced the lowering of its prices.

E.ON said that a typical dual fuel customer will see the bill rise by GBP0.31 a day. Despite this, the company claims that the average dual fuel customer could still save with E.ON compared to British Gas’s post-increase prices.

E.ON stated that more than 550,000 customers are unaffected by its price increase announcement as they are already on its Price Protection or Fixed Price products, including more than 280,000 customers with StayWarm, E.ON’s fixed price scheme for customers over the age of 60.

Graham Bartlett, managing director of E.ON Energy, said: We realize the impact this price increase will have on our customers and we’re doing everything we can to minimize this. Our announcement has been made in response to sustained pressures from the wholesale market.