Labour claims the Green Deal, which aims to help deliver cheap electricity to households, is getting out of control.
Some 12 companies have also written a letter to the government saying they need more funding for the scheme, the Daily Telegraph reports.
The firms say they will not commit to any further development until they receive £240 million from the coalition.
E.ON, Marks & Spencer, Scottish Power and npower are among the organisations that signed the letter.
They are all members of the Green Deal Finance Company, which was set up in March to promote the initiative.
Shadow climate change minister Luciana Berger said the letter is "a real blow to the government's plans for the Green Deal and further evidence of a policy that is spiralling completely out of control".
The Green Deal was established under the Energy Act 2011 and will mean homeowners do not have to pay upfront costs for eco-friendly upgrades to their houses.
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