The Guardian reports that environmental campaigners are again suing the European commission over the sustainability of the EU's biofuels policy.

The paper says that ClientEarth, Friends of the Earth Europe, Fern and the Corporate Europe Observatory say the commission has refused them access to information on the voluntary certification scheme used to ensure compliance with EU sustainability criteria.

The groups accuse the commission of a lack of transparency, saying that neither assessment criteria nor information on other schemes being considered have been made publicly available.

James Thornton, ClientEarth's chief executive, said that the policies were too important to decide in secrecy. "The amount of money at stake over Europe's biofuels policy is colossal, and so is the potential for environmental devastation," he said.