The Green Party plan of providing insulation free to every home, would be much fairer than the 50% discount announced by Gordon Brown today.
Under the government's fuel deal, those who can afford to insulate will be offered money off, while less well-off households will have to navigate means-testing to access free insulation.
Experience shows that these hurdles often lead to the most needy being excluded.
Greens are already implementing non-means-tested, universal free insulation in Kirklees, Yorkshire, and aim to roll it out to more areas.
Dr Lucas said: "As with Tory school vouchers and patient passports, this 50% discount is only a subsidy to those already able to pay for insulation. Over one in six British households are already in fuel poverty, and if you can't afford to heat your home, you can't afford to insulate it.
"The government have promised free insulation to pensioners and the poorest, which Greens already forced through the last Labour administration in London. This does help but it requires people to jump through bureaucratic hoops to access the insulation they need. Many of the most needy aren't able to do that, for example because they have learning difficulties or have to move house frequently.
"Green councillors in Yorkshire have already insulated 11,000 homes totally free with no means testing, with 30,000 more to come. If Gordon Brown wants to solve fuel poverty he should come to the experts."