WASHINGTON – Indian tribes are subject to federal labor laws, an appeals court ruled Friday in a case that could lead to stricter labor protections – and more unions – at the nation’s booming Indian casinos.

A three-judge panel of the U.S. Court of Appeals for the District of Columbia Circuit rejected arguments from a wealthy Southern California tribe that as a sovereign government, it should not be subject to those laws.

“Tribal sovereignty is not absolute autonomy, permitting a tribe to operate in a commercial capacity without legal constraint,” said the opinion written by Judge Janice Rogers Brown.

The ruling stemmed from an organizing dispute at a casino run by the San Manuel Band of Mission Indians, 60 miles east of Los Angeles, where a union filed a complaint with the National Labor Relations Board arguing that another union was getting preferential access.