The rush for biofuel altern-atives to petrol has had a huge impact on global food stocks, increasing the cost of food by 75%, according to an authoritative report for the World Bank.

Details of the report come just ahead of the publication of the UK Government's own study on the impact of biofuels, expected to come to the similar conclusion that planting crops for fuel instead of food has had "significant" distorting effect on food prices.

The report by Professor Ed Gallagher, head of the Renewable Fuels Agency, is due to be published on Monday by the Department for Transport and will add to the pressure on the government to alter EU policy targets of having 10% of petrol made from plant-derived fuels by 2020.

Biofuels - derived from corn, rapeseed, palm oil and soya - as an alternative to petrol and diesel were seen as the environmentally friendly solution to global warming and dependence on imported oil. Now they are being identified as one of the causes of rocketing food prices and starvation.

Since April, all petrol and diesel in Britain has had to include 2.5% from biofuels but the government is now being faced with mounting evidence that the drive for biofuels will only push food prices higher. The leaked World Bank report lays bare the commonly held belief that the growing consumer wealth of developing countries like China and India is a major factor in food-price rises.

It concludes that demands from these new markets has not had a major effect on prices while successive droughts in Australia had only a marginal impact.

The World Bank report contradicts US government claims that using plants to produce fuel contributes less than 3% to food prices and commentators have concluded the report was delayed to avoid embarrassing President George Bush.

The issue will be discussed at the G8 meeting of world leaders in Hokkaido, Japan, this weekend, and on Monday the European Parliament's Environment Committee will consider a motion to scrap the 10% target for biofuels.

Friends of the Earth biofuels campaigner Kenneth Richter called on MEPs to ditch the controversial biofuels targets and vote instead to double the fuel efficiency of new cars.

He said: "This report shows that when MEPs vote on biofuels targets next week they will have the fate of millions in their hands.

"Finding enough land to grow 10% of Europe's transport fuel will lead to more hunger and suffering."