A federal judge Thursday stopped the biggest phosphate company in the world from expanding a Polk County mine, ruling that a federal permit to destroy wetlands was probably issued illegally. The ruling by U.S. District Judge Henry Lee Adams granted a motion by a coalition of environmental groups for a temporary restraining order against Mosaic Fertilizer. The decision temporarily prohibits the company from proceeding with new excavations at its South Fort Meade mine, where strip mining had already begun. In Adams' ruling, the judge said the environmental groups would likely be able to prove that the Army Corps of Engineers permit issued last week was "arbitrary and capricious." He wrote that the public interest would be harmed if mining were allowed to proceed during the rest of the case. The environmental groups suing the corps include the Sierra Club and ManaSota-88.