The US Environmental Protection Agency (EPA) last week upheld the national mandate to use biofuels. The decision was made despite opposition from livestock and environmental groups, which say that the expansion of corn (maize) ethanol is pushing up food prices and damaging the environment.

EPA administrator Stephen Johnson denied the request of Rick Perry, the Republican governor of Texas, to halve the 'renewable fuels standard', which requires the nation to produce 34 billion litres of ethanol in 2008. Perry had argued that livestock producers in his state spent an additional US$1.2 billion on corn feed between 2004 and 2007, a trend that he linked to the expansion of biofuels.

But Johnson says that repealing the standard would do little, if anything, to bring corn prices down. He also says that the EPA's analysis found no evidence that the mandate is damaging the national economy.