Those increases will take effect on 1 December, and will see the typical dual fuel bill rise to £1,459. Last year Npower increased prices by 8.9 per cent on 26 November.
Paul Massara, CEO RWE Npower, said:
I know that any increases to household bills are always unwelcome, and this is not a decision that we have taken lightly. We will continue to take steps where we can to reduce the impact of the external influences on energy bills.
Massara also slammed a proposal unveiled by Labour leader Ed Miliband to fix prices. Massara said that the policy "may appear superficially attractive" but would "not lead to lower sustainable prices going forward because it doesn’t cut the growing costs of supplying energy."
The energy boss said that "only 16 per cent of the bill is under our control and imposing price controls discourages investment, increases uncertainty and ultimately leads to higher prices"
Npower offers a price protector plan that offers a price ceiling on bills until March 2017.