Telegraph: Environmental campaigners have called for a change in policy on biofuels after a report that they have caused a 75 per cent increase in food prices. An unpublished World Bank study claimed the EU and US drive towards biofuels was having a massive impact on both food supply and prices. The US Government had claimed that biofuels – mainly ethanol produced from crops such as corn, palm and soya – was responsible for only a three per cent rise in food prices. President Bush …