Two new power stations that use a fuel critics say contributes to the destruction of rainforest in south-east Asia may be built in the UK through subsidies added to customer bills.
The two plants in the south of England would run on palm oil, which in many cases is sourced from plantations sited on cleared rainforest land.
They are among more than 30 new power stations at various stages of the planning process that propose to burn wood and other plant materials, as owners try to take advantage of hundreds of millions of pounds of subsidies to cut reduce greenhouse gas emissions.
However, experts have warned that as well as being linked to tropical rainforest destruction – and the survival threat to the orang-utan in the wild – crop-fuelled power stations will push up food prices by competing for land, and in many cases will not even cut greenhouse gas emissions.
UK government policy insists companies use only "sustainable" sources, but campaigners claim the rules are too relaxed and it is too hard to enforce such standards on plantations far from the UK, especially when other – non-certified – land could be cleared of forests to make way for displaced food growing.
"The trouble is their sustainability standards amount to little more than greenwash: they claim to set a standard but all they are saying is you need to comply with a couple of criteria in European law that are vague," said Harry Huyton, head of climate change for the RSPB. "Once you build them [the plants] they are here to stay: they have a shelf-life of 30 years or longer and they need biofuel to feed them."
Campaigners are now urging ministers to review the policy on bioenergy that is currently expected to deliver more than half of the government's target to generate 15% of energy from renewable sources by 2020.