The installation of measures to help homes save energy has collapsed as a result of Government policies, campaigners have said.
The number of energy efficiency measures installed under national programmes fell 60% in the past year, down from a peak of 1.65 million in 2012/13 to 661,000 in 2013/2014, research commissioned by the Energy Bill Revolution campaign showed.
The number of energy efficiency measures, which include c avity wall, solid wall and loft insulation and new boilers, was set to fall again by nearly a quarter (23%) this year, to 507,000.
It would see installation rates at their lowest level for more than a decade, the study by the Association for the Conservation of Energy said.
This was despite vast numbers of homes still needing installation of energy efficiency measures, as 13 million households did not have energy saving condensing boilers, five million could benefit from cavity wall insulation and 7.5 million needed loft insulation.
The huge drop was down to the Government's decision to axe the "warm front" scheme, the only Government-funded energy efficiency programme for poor households, and failures in its other energy saving schemes, the campaigners claimed.
The Government's flagship green deal programme, which provides loans to householders for installing energy saving measures, had been an abject failure, the campaigners added.
And the "energy company obligation", which requires suppliers to provide energy efficiency measures to poor and vulnerable households with the costs added to consumer bills, was poorly designed, they claimed.
Its failure to deliver on energy efficiency had been exacerbated by cuts to the scheme by the Government in a bid to reduce consumer fuel bills, the campaign - an alliance of 180 charities, businesses and unions campaigning to end fuel poverty - said.
The existing programmes were failing to tackle fuel poverty and would miss recommended targets from the Government's advisory Committee on Climate Change for insulating all remaining cavity walls and lofts by 2015, and 2.2 million solid walls by 2022.
The alliance was calling for home energy efficiency to be made a UK infrastructure investment priority.
All six million low income homes should be raised to a decent level of energy efficiency, judged as scoring a C grade on their energy performance certificate (EPC), by 2025, which would require more than trebling the number of measures being installed each year.
Extra costs should not be put on consumer bills, but revenue from carbon taxes levied on generators for the pollution they created should be used to provide long-term funding for energy efficiency, the campaign group said.
Ed Matthew, director of the Energy Bill Revolution campaign, said: "The Government's energy efficiency policies are in free fall.
"As a result, fuel poverty is getting worse and people are dying.
"The Government must make home energy efficiency an infrastructure investment priority to put the funding in place to end this scandal once and for all."
He added: "What's unique about energy efficiency is it does more than any other energy policy about energy security, fuel poverty and carbon emissions.
"It has a multiplicity of benefits."
A spokesman for the Department of Energy and Climate Change said: "694,000 homes are now warmer and cheaper to run thanks to energy-saving measures installed under the Green Deal and the energy company obligation (ECO)."
He said the Government had extended the support given through ECO to 2017, giving clarity to the industry and supply chain.
And he said: "Our new Green Deal Home Improvement Fund, offering money back for making energy efficient home improvements, has already seen £16.5 million issued in the first three weeks."
Shadow energy and climate change secretary Caroline Flint said: "The most sustainable way to cut people's energy bills for the long-term is to invest in insulation and save the energy that escapes through our windows, walls and rooftops.
"These figures show that not only has David Cameron failed to stop the energy companies from overcharging, the number of households getting help to insulate their homes has also collapsed.
"This terrible reduction in insulation measures could not have come at a worse time. Because of David Cameron's failure to tackle energy bills people are desperate for help, but the Government's energy efficiency schemes clearly are not working.
"That's why the next Labour Government will freeze energy bills for 20 months, reform the energy market, and help households make the energy efficiency improvements we so desperately need."