Money meant to help vulnerable people become more energy efficient may not be going to the needy, the Parliamentary Public Accounts Committee has said.
Are Warm Front funds going to the right people?
The government pays out £150m each year in grants under its Warm Front Scheme.
The committee estimated that £100m of the money granted is going to people who do not need the money.
It added that the government department administering the scheme used the wrong measures for assessing if someone needed help.
'Waste of money'
Consumer group Energywatch expressed alarm at the criticism of the Warm Front scheme, which is administered by the Department for Environment, Food and Rural Affairs (Defra).
"Warm Front funds must reach the poor," said Allan Asher, chief executive of Energywatch said.
"The scheme should focus on alleviating fuel poverty. At the moment it is proving to be a waste of money."
The Warm Front Scheme replaced the Energy Efficiency Scheme in June 2000 and is a key part of the government's long-term strategy to eradicate fuel poverty.
A household is deemed to be suffering fuel poverty if more than 10% of income is spent on energy.
A Defra spokesman told BBC News Online that they welcomed the comments of the Public Accounts Committee and were carrying out an ongoing review of the Warm Front Scheme.
"We will look at the conclusions of the committee carefully as we examine targeting and the eligibility criteria that we use," the spokesman said.
"However, since the Warm Front Scheme began more than 700,000 households have been helped."