Environmental campaigners are urging Liberal Democrat ministers to do more to defend green policies in the coalition, with a raft of energy-saving and carbon reduction measures under threat in George Osborne's Autumn Statement.
David Cameron has put all green taxes under review, despite repeated promises by the Chancellor that the measures make "economic sense".
Business Secretary Vince Cable led the Lib Dem calls last week to protect green taxes – which help the renewable energy market and limit carbon pollution – warning it would be "short-sighted and foolish" to scrap them. Yet there are fears the Lib Dems will go along with weakening the levies in the interests of political stability for Mr Osborne's statement in December, and in the face of rising costs from energy suppliers.
The situation is particularly acute since Ed Miliband unveiled a price freeze on fuel bills for two years if Labour is elected in 2015 – prompting energy firms to blame green taxes for their huge bills.
In 2011, the Chancellor announced the carbon price floor – a tax on industry of £16 per ton of carbon emitted, which should rise to £30 by 2020. But this is thought to be under review, along with the Energy Companies Obligation (Eco), which ensures firms are insulating fuel-poverty homes.
In opposition, Mr Osborne argued that the Tories should "take the lead" in promoting green growth.