The claim comes as MSPs clash on the impact of rising energy prices and the actions of the "big six" energy companies.
Labour MSP Jackie Baillie, who will lead a debate on the problem today, said ministers must do more and called on the SNP to back her party's plan for a price freeze.
"Fuel poverty is on the rise. It is far higher than official numbers suggest, yet despite the increase the Scottish Government has failed to spend its budget on prevention," she said. "It is unacceptable that the Scottish Government has underspent its budget for fuel poverty, delayed distributing this to local authorities and watched companies which install insulation go to the wall."
Margaret Burgess, the Scottish Government housing minister, said the UK Government is making the problem worse.
Ms Burgess said: "We are doing everything we can within our limited powers to provide a wide range of energy efficiency measures to individual households and to local authorities.
"Earlier this month we enhanced our support for those faced with fuel poverty by enabling increased uptake of our Energy Assistance Scheme.
"But we need the full powers of independence to fully tackle all the causes of fuel poverty."