The Environment Agency faces a major challenge in the High Court in March over its powers to police a revolutionary waste oil process. It is being taken to the High Court by Petrus Oils, which is challenging moves to revoke a licence granted for a plant at Stoke on Trent which converts waste oil into useable products. The plant is the only one of its kind, though others are being constructed in Salt Lake City and Dubai. Petrus has already been cleared of 11 criminal charges brought against it by the Environment Agency. On that occasion, the judge branded the prosecutions as oppressive, manifestly unfair and an affront to the public conscience."