Protest groups including UK Uncut and Fuel Poverty Action will demonstrate against energy providers Npower and British Gas over the rise in energy prices.

UK Uncut said more than 1,000 demonstrators are expected to take part in the protests in London.

The anti-austerity groups plan to march on Npower offices with a coffin filled with bills and hold a "speak-out", where those hardest hit by "fuel poverty" will speak of their experiences.

In addition, protests will be taking place in Oxford at the new British Gas headquarters as well as Lewes and Bristol.

UK Uncut said Npower has been chosen as the main London target as it received 202 complaints per 100,000 customers between April and June.

"The fact that people are dying of fuel poverty as Npower and other energy companies rake in the money is a scandal," said Susan Jarrett, a member of UK Uncut.

She added: "The government is not only unnecessarily cutting our services in the name of austerity, but are allowing these energy companies to literally get away with murder which is why we are fighting back today."

A spokesperson for Npower said: "Energy companies are part of the solution, not part of the problem.

"Although energy suppliers like Npower only control around 16% of the total cost in people's energy bills, we employ more than 100 people whose sole job is to provide support to our most vulnerable customers and deliver real savings through energy efficiency."

Price Hikes and Bonus Pledges

The Big Six account for 99% of the UK's energy sector.

While Npower said it will raise household charges for electricity and gas by 9.3% and 11.1% respectively, Centrica said it will raise its household charges for electricity and gas by an average of 9.2% from November.

Meanwhile, its subsidiary British Gas said its electricity and gas prices will rise by 10.4% and 8.4% respectively, from 23 November.

SSE also announced it will raise its charges for electricity and gas by an average of 8.2%.

However, Ofgem data has revealed that wholesale energy prices have only risen by 1.7% despite the big six energy companies in Britain blaming this for hiking up household bills by 11.1%.

Meanwhile, Npower's chief executive Paul Massara refused to give up hisbonus in light of the public outcry at the soaring cost of energy bills.

Centrica chief Sam Laidlaw's recent pledge to forgo his annual £2.6m bonus from a total pay package for 2012 that stood at £4.96m (€5.86m, $7.92m) was labelled a "gimmick" by Massara.

Massara added that he would only receive his £150,000 bonus if he hit targets tied to employee and consumer satisfaction.

British Gas had not responded to a request for comment at the time of publication.