POCATELLO -- A federal judge is allowing nine separate parties join a lawsuit challenging plans by the J.R. Simplot Co., to expand its phosphate mining operation in southeast Idaho.

The ruling by Chief U.S. Magistrate Mikel Williams allows the parties, ranging from city and county governments in Idaho and Wyoming to a steelworkers union, to intervene in the lawsuit on behalf of Simplot.

The lawsuit was initially filed earlier this year by environmentalists seeking to halt the company's plan to develop new mining deposits at its Smoky Canyon mine in the Caribou-Targhee National Forest.

The nine parties allowed to intervene claim they will lose jobs and revenue if the mine is not allowed to expand and continue operating.