The British government said it would slow the introduction of biofuels to address concerns that switching the use of land could exacerbate climate change and push up food prices.

The government accepted the conclusions of a report it commissioned from Ed Gallagher, chair of the Renewable Fuels Agency, which called for a more cautious approach until more evidence was available.

"The Gallagher report ... concludes that the introduction of biofuels should be slowed until policies are in place to direct biofuel production onto marginal or idle land, and that these are demonstrated to be effective," Transport Secretary Ruth Kelly told parliament.

"In short, the report concludes that the government should amend but not abandon its biofuel policy," she added. "I agree with these key findings."

Biofuels are mainly produced from food crops such as wheat, maize, sugar cane and vegetable oils and are seen as a way to cut greenhouse gas emissions that contribute to climate change.

Critics say diverting land from food crops to produce biofuels has helped push up global food prices and in some cases has led to the destruction of rain forests.

The EU's proposal to get 10 per cent of road transport fuels from renewable sources, such as biofuels, by 2020 has faced growing criticism.

"This review sends a stark message - using food crops to fuel our cars risks making climate change worse and increasing food prices for the world's poorest people," said Doug Parr, chief scientist of environmental group Greenpeace.

"Gordon Brown must now follow one of the key recommendations of his own report and call for an end to the EU's hastily adopted and potentially damaging biofuel targets."

Clare Wenner, head of biofuels for the Renewable Energy Association, said the measures would create a difficult environment for biofuels investors.

"The slowdown is disappointing but when you couple that with yet more reviews, yet more conditions ... it makes the whole environment very difficult," she said. "My big fear is that investors in this country will walk."

"Over the last 12 months, new research has identified that land use change causes significant greenhouse gas emissions, sufficient in many cases to overcome the savings from biofuels for several years," Dr Gallagher told Reuters in an interview.