It will take 28 years to eradicate fuel poverty if spending on energy efficiency measures continues at the current rate, according to the Scottish Greens.
Ministers have set a goal to ensure that by November 2016, so far as is reasonably practicable, people are not living in fuel poverty in Scotland.
But experts have warned that there is no chance of meeting the target because not nearly enough households are given the help they require each year.
A household is defined as being in fuel poverty if, in order to maintain satisfactory heating, it would be required to spend more than 10% of its income on all fuel use.
Scottish Government figures showed that 940,000 households were in fuel poverty in 2013.
The Greens have urged ministers to dramatically increase investment in energy efficiency measures for housing to speed up progress.
The party warned that at the current rate, eradicating fuel poverty will take decades.
Through Home Energy Efficiency Programmes (Heeps), they say the Government helped just 33,000 homes in 2013/14. Measures included new boilers, gas central heating and wall insulation.
At a meeting of Holyrood’s Economy Committee last week, Norman Kerr of charity Energy Action Scotland told MSPs that “the fuel poverty target will not be reached, and by some considerable way”.
Patrick Harvie, the Greens’ economy and energy spokesman, said: “The Scottish Government pledged to eradicate fuel poverty by November 2016, and everyone except the Government itself seems to have admitted that there’s no chance now of hitting this target.
“The number of households unable to heat their homes has been growing, not shrinking, and while some important powers are yet to be devolved Scottish ministers could be doing much more with the powers they already have.
“We know that investing in energy efficient homes is one of the best ways to tackle fuel poverty, but if the Government continues at its current rate, it will take decades for all vulnerable people and families in Scotland to have decent warm homes.
“Ministers have agreed with Green calls for warm homes to become a National Infrastructure Priority, but we need to see that pledge backed with a serious increase in the forthcoming budget, and for that funding to be spent in full.
“We’ve also proposed the creation of thousands of apprenticeships in energy efficiency to tackle the skills gap and get the sector up to capacity.
“We will continue to press on these issues so we end the scandal of people being unable to heat their homes in energy-rich Scotland, and so we create quality construction jobs and get our climate targets back on track.”