Millions of SSE customers will see an average 8.2% rise in the cost of their gas and electricity bills from next month.
The energy giant has blamed the increases on the rising cost of purchasing wholesale energy, transporting this energy to households and Government-imposed levies.
The company says that for a typical dual-fuel customer, wholesale energy prices had gone up 4%, paying to use delivery networks was 10% more costly, and Government levies were 13% higher.
From 15th November, SSE's average annual standard dual fuel energy bill, for those who pay by monthly Direct Debit and receive a paper bill, will be £1,380. This is up from £1,274 and represents an increase of around £2 per week or £104 over the year.
These costs are based on a typical consumption of 16,500kWh of gas and 3,300kWh of electricity per year.
The price hike will impact 4.4 million electricity customers and 2.9 million gas customers, though those on fixed-price tariffs will be shielded from the changes. SSE is pledging not to raise prices again before Autumn 2014 at the earliest.
Customers that will be affected will be notified by 15th October.
SSE has gone on the attack about the price rise, laying the blame on politicians.
Will Morris, Group Managing Director, Retail, said: "We're sorry we have to do this. We know we will come in for a great deal of criticism for this decision and politicians will no doubt be lining up to condemn us.
"But over many years policymakers themselves have failed to highlight adequately the cost to consumers of the policies they have pursued in Government. They can't expect to have power stations replaced with new technologies, the network to be upgraded and nationwide energy efficiency schemes all to be funded for free."
SSE said that by transferring the costs of environmental and social policies from energy bills to the taxpayer, the move would immediately take £4 billion of UK energy bills. This would cut a typical dual fuel bill by around £110 this year alone, according to SSE.
SSE said that it strongly believes that rising prices do not necessarily have to mean higher bills as falling consumption in recent years mean people are spending less. Though arguably rising energy bills have caused customers to cut down on what they use.
However, National Debtline reported that it had received a record 15,502 calls from people seeking help with energy debts in the first six months of this year. This is up 10% on last year, and 111% compared with five years ago. The charity said it got more calls on energy bill problems than payday loans and mortgage or rent arrears.
SSE is the first of the 'big six' energy companies (the others are British Gas, EDF, E.On, npower and Scottish Power) to announce a price increase this year.
It was also the first last year when it announced a price increase of 9% in August.
The move sparked a domino effect among the big six energy companies which duly followed SSE by announcing price rises of between 6% and 10.8% between October and December.
The same is likely to happen this year, so the time is now to shield your household from price rises.
The cheapest tariffs
Switching onto a cheaper deal or fixing your bills can shield you against the price rises to come.
Below are the cheapest tariffs available right now.
Savings vs typical bill*
Online billing. Paper bill available for extra £12 pa.
Standing charge and unit rates frozen until March 2014.
Guaranteed to be below Sainsbury's Clear & Simple tariff unit rates until 31st October 2014
£30 per fuel until 31st October 2014
Online management only
*Savings against an average bill of £1,420 as determined by Ofgem
All calculations are for an average usage dual fuel household paying by monthly direct debit. Average usage as defined by Ofgem is 16,500 kWh pa of gas and 3,300 kWh pa of electricity.
First Utility recently announced it would freeze prices for variable tariff customers, so you can get access to the cheapest rate that will stay the same at least until the winter is over.
See if you could pay much less for your gas and electricity with our quick and easy comparison service