Scottish Power is hiking gas and electricity prices by 5.5 per cent on 1 June, the company announced on Friday.
The cost for a typical household on a dual-fuel standard tariff will rise by £63 to £1,211.
The rise will affect a third of Scottish Power’s customers, around 960,000 households. Those on fixed tariffs will not see their bills increase, the company said.
Scottish Power blamed the increase on rising wholesale gas and electricity prices compulsory costs such as upgrading meters.
It becomes the latest energy supplier to hit customers with higher bills after EDF Energy announced last week that it would raising the prices by 1.4 per cent, for 1.3 million households from June.
The energy provider said it would increase its standard variable electricity tariff by £16 a year, taking the dual fuel cost for an average household to £1,158 per year. The company said there would be no change to gas prices.
That came just days after British Gas raised its prices, drawing heavy criticism from MPs, with Labour shadow cabinet minister John Trickett describing the move as a “slap in the face” for customers.
The energy giant said prices will rise by an average of 5.5 per cent, meaning the cost of the standard tariff will increase to £1,161. An estimated 4.1 million customers will see their bills increase by an average of £60 per year.
On Thursday, research revealed that a quarter of a million more customers face rising energy bills in the next three months as 130 fixed rate deals come to an end.
Victoria Arrington, spokesperson for price comparison and switching service energyhelpline said the energy price wave was now “full on”.
She added: “Scottish Power’s rise is only the latest of the stinging hikes eating into the pay cheques of people across the UK, and this is the biggest price rise so far from a major supplier – a real whopper at 5.5% with 960,000 homes affected if they don’t switch.
“No energy customer should be on a standard tariff as they are almost always bad value for money.
However, she said there were some “phenomenal” energy deals available for those who switch with the cheapest available now £806, or a £405 average saving on Scottish Power’s standard tariff.
