The National Labor Relations Board is seeking a federal injunction to require coal operator Massey Energy to rehire 85 union members at a West Virginia mine.

An NLRB administrative law judge ruled last November that Richmond, Virginia-based Massey violated federal labor laws by refusing to rehire the miners after acquiring the mine from Horizon in 2004.

On Thursday, the agency is scheduled to argue its contention that Massey and its Spartan Mining subsidiary will keep violating federal labor laws without an injunction.

Massey has tried to get the NLRB request dismissed. The company contends former employees weren't hired because better replacements were found. It also says it didn't have to bargain with the United Mine Workers because the subsidiary that acquired the mine wasn't a legal successor to Horizon.