Economic experts agree that a programme to insulate homes is one of the best things you can do to stimulate the economy, creating jobs in every part of the country.
The government is under pressure to deliver on its manifesto commitment to invest billions of pounds in insulating homes as part of a green recovery from the coronavirus pandemic.
The Conservatives promised £9.2 billion to improve the energy efficiency of homes, schools and hospitals as part of their election bid last year.
Government advisers the Committee on Climate Change are among those calling for major investment in making homes more energy efficient to boost jobs, cut fuel bills and tackle greenhouse gas emissions from buildings.
But a report in the Financial Times suggests Downing Street chief adviser Dominic Cummings is holding up the investment.
Ahead of expected announcements on the pandemic stimulus, campaigners and industry bodies are urging the Prime Minister to deliver on the manifesto commitment to make homes warmer as part of efforts to reboot the economy.
The National Insulation Association (NIA) called for a street-by-street home energy efficiency scheme to support the economic recovery and protect the NHS from the costs of treating illness caused by living in cold draughty homes.
The industry body said a homes upgrades grant scheme focusing on fuel-poor homes, as part of the promised funding, should be launched this year.
In its first year, with £150 million of funding, it would deliver deep retrofits to 10,000 homes with a mixture of insulation and low-carbon heating systems, creating 500 jobs and saving each household £330 a year on average.
And delivering the full five-year £2.5 billion policy would deliver home retrofits for 185,000 homes, create 8,000 jobs and deliver £1 billion savings for the NHS and cut carbon emissions by 17 million tonnes, the NIA said.
The organisation said a street-by-street approach led by local authorities, focusing on the fuel-poor and incentivising households who are able to pay with subsidies would be the best way to deliver the upgrades.
Derek Horrocks, chairman of the association, said: "The benefits that come from improving the quality of our homes are substantial on any level but particularly now as we come out of the crisis.
"If we are going to build back better, it is now time to turn promises into action.
"After being hit hard by the pandemic, the industry is ready and waiting to respond to an increase in demand - but the signal of certainty must first come from the Government."
Campaigners have also warned against ditching the manifesto pledge to invest billions in energy efficiency.
Ed Matthew, associate director of climate think tank E3G, said: "Economic experts agree that a programme to insulate homes is one of the best things you can do to stimulate the economy, creating jobs in every part of the country and saving households hundreds of pounds.
"It is also an investment which is mission critical to reach net-zero emissions and can save thousands of lives, with 10,000 people dying every year from living in cold homes."
He warned that ditching the manifesto pledge would undermine "the most effective economic and social project to ensure we can build back better".
Emily Beament is the PA environment correspondent.