Georgia and 24 other states have asked the U.S. Environmental Protection Agency to delay issuing a controversial rule regulating mercury saying it could threaten the stability of the nation's electricity supply and drive up prices.

The rule, scheduled to be issued next month, would require utilities including Georgia Power and others operated by its parent company, Atlanta-based Southern Co., to close or retrofit several of its coal-fired power plants.

Georgia Power has said complying with these regulations will cost from $741 million to nearly $3 billion and lead it to close or refit six additional coal or oil-fired plants by 2015. The utility can recoup those costs through consumer bills.

The states filed an amicus brief in U.S. District Court late Monday.