Amid signs of a growing backlash against biofuels in the wake of the worst food price spike since the 1970s, the International Energy Agency said that the crop-based fuel was vital to meeting current and future demand.

Biofuels already make up about 50 per cent of the extra fuel coming to the market from sources outside the Opec's oil cartel this year. This explains why fears of a retreat from biofuels this week helped drive oil prices to record levels.