Almost 170,000 households could be forced into fuel poverty if more suppliers follow Scottish Power in raising prices.

The company last month raised gas prices by 19% and electricity costs by 10%. The rises come into force at the start of August.

In a response to questions from Labour, Infrastructure Secretary Alex Neil said that up to 169,000 more households could suffer if the hikes were replicated by more firms.

An estimated 770,000 households in Scotland are already in fuel poverty - defined as spending 10% or more of household income on domestic fuel bills.

Labour Leader Iain Gray said: "These shocking figures expose the harsh reality of big power companies ramping up fuel bills.

"Price hikes like this affect every Scot, but they will have a disproportionate impact on those who are on the lowest incomes.

"It is our duty to help the poorest and most vulnerable in our society, who will be hit hardest by these price increases, through these tough times.

"With more than one in three Scots now struggling to heat their homes it underlines just how wrong the SNP's decision to slash the fuel poverty budget by almost a third was.

"I urge the SNP government to wake up to the reality facing hard-pressed Scots and urgently reverse the cut to the fuel poverty budget."

A Scottish Government spokesman said: "There has been good progress on improving the energy efficiency of Scotland's homes but, time and again, the Scottish Government's efforts to lift people out of fuel poverty are being undermined by high fuel prices.

"It is scandalous that so many people are suffering from fuel poverty in energy-rich Scotland, and the Scottish Parliament needs full powers so that we can do more.

"Ministers met with Ofgem and support the work of Ofgem to further protect consumers, deliver transparency on energy prices and ensure companies treat their customers fairly."

The spokesman added that Mr Gray's claims about the Scottish Government are wrong, saying: "The Scottish Government's universal home insulation scheme's budget has actually been increased by 25%, from £10million to £12.5million, and is helping people right across Scotland."