Efforts to end fuel poverty are being undermined by energy companies' price increases, the Deputy First Minister said.

Nicola Sturgeon called on UK Government ministers to take a firmer stance with the firms and help thousands who are struggling to pay their fuel bills.

She spoke out before a national conference on fuel poverty, organised by Energy Action Scotland.

Scottish Government figures show 658,000 households were in fuel poverty in 2010, meaning they have to spend at least 10% of their income on energy.

Figures for 2011 are predicted to exceed 800,000.

Ms Sturgeon is demanding action from Westminster to tackle the problem.

"Scotland is an energy-rich nation and everyone should live in a safe, warm, affordable home," she said.

"This Government is tackling fuel poverty head-on and has a broad range of measures in place to help Scottish households to cut their energy bills.

"Just last week we announced an additional £6 million for the Universal Home Insulation Scheme which will help up to 10,000 households to cut their energy bills this winter.

"It is a matter of great concern that our efforts to reduce fuel poverty continue to be undermined by price rises by energy companies.

"The UK Government, which has responsibility for this area, is simply not doing enough to regulate the market and we are urging them to take a firmer stance with energy companies to help the thousands of households who are already struggling to pay their bills."

The Energy Action Scotland conference will consider how fuel poverty can be eradicated.

Charity director Norman Kerr said: "It is important to ensure that all angles are looked at in the bid to end fuel poverty. Technologies are available to improve the energy efficiency of homes but better ways are needed to both inform and make them accessible to the public. Who bears the cost must also be considered, as this currently adds to bills.

"Meanwhile, household budgets are under pressure and the effects are especially felt by those on a low income."

The conference is sponsored by energy firm SSE, whose chief executive Ian Marchant said the company remains committed to providing help and support for customers.