Energy provider npower has confirmed its standard gas and electricity prices will rise by more than 10 per cent.

The company has not yet confirmed exactly how much their prices will increase but a spokesman revealed the percentage increases will be in double figures.

It is the first time an energy supplier has increased standard rates since last spring's price cuts.

Npower's hike is likely to be the first of a flurry of similar increases across the sector as suppliers seek to pass on rises in the cost of wholesale energy prices.

Npower, which is owned by German company RWE, has already increased its online tariff for new customers, upping bills by 17 per cent the week before Christmas.

British Gas parent Centrica also announced last month increases to its market tracker price, increasing bills by 13 per cent for gas and 15 per cent for electricity.

It also warned less than two weeks later that wholesale prices left the energy industry facing a "difficult environment" in 2008, signalling that prices were set to rise across the board.

Npower's announcement came as no surprise to industry experts, who saw the group's online price hike as a sign of a wider tariff review.

Tim Wolfenden, head of home services at uSwitch.com, said: "Price rises have been on the horizon for some time.

"Ever since British Gas and Npower announced price increases on their market trackers and npower followed this up with a price hike on its online plan, it has been clear that prices are going to be heading north again, with the smart money on a 15 per cent rise.

He warned that npower's decision to up standard rates will "give competitors the green light" to follow suit.

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