The Bush-administration is under fresh legal assault over the us Environment Protection Agency's (epa's ) recent mercury emission cut norms for coal-fired power plants. Eleven states filed a lawsuit against it on May 18, 2005, opposing the move to let such plants trade in mercury emissions.

epa's rule directed these plants to cut 70 per cent emissions by 2018 through a cap-and-trade system: plants emitting less mercury than the capped amount can sell credits to plants emitting more. epa also took their mercury emissions off the list of air toxins so as to apply the cap-and-trade approach, forbidden for toxic chemicals under the Clean Air Act. Nine states sued the federal government against the move soon after.