Campaigners warned today that hundreds of thousands of households are living in "fuel poverty" because of rising costs.

Some 600,000 households and 100,000 children in Scotland have been hit by rocketing fuel prices between 2003 and 2006, they said.

A household is said to be in fuel poverty if it needs to spend more than 10% of of its income to maintain satisfactory heating, according to a UK government definition.

Today, children's charities Barnardo's and Save the Children teamed up with consumer group energywatch Scotland to urge the Westminster Government to take action.

As winter approaches, they are calling for the introduction of so-called social tariffs in the Energy Bill, to be announced during this week's Queen's Speech.

Such a move would require energy firms to help ease the burden on consumers who cannot pay greatly increased heating costs.

So far, campaigners say, voluntary efforts by companies have been insufficient.

"The combined voluntary efforts of the industry nowhere near address the impact that high prices have had on the fuel poor," they said.

Consumers were "stuck in a lottery", they went on, "with the amount of support on offer being wholly dependent on an individual supplier's commitment."

Graham Kerr, of energywatch Scotland, said: "Regardless of further price rises, hard-pressed consumers should be able to take comfort from knowing that there is a minimum standard of help available.

"Only by introducing the power to require suppliers to offer social tariffs in accordance with minimum standards will government ensure that all suppliers play their part fully."

Claire Telfer, of Save the Children, added: "Another winter is fast approaching and far too many children are living in cold, damp homes.

"The consequences of living in fuel poverty are misery, discomfort, ill health and debt."