The federal 7th Circuit Court of Appeals today upheld Indiana's right to work law as constitutional.
The ruling comes just two days before the law is challenged at the Indiana Supreme Court.
Indiana's right to work law bans union contracts that require nonmembers pay fees for representation.
The International Operating Engineers union filed two lawsuits in the wake of the bill's passage in 2012 – one in federal court, another in state court.
The union hasn't had any luck in federal court. The law was upheld by a district court last year and Tuesday, a three-judge panel at the 7th Circuit ruled two to one in favor of right to work.
The ruling says federal labor law, and previous court rulings, give states the right to regulate union contracts.
Union spokesman Ed Maher says while the 7th Circuit ruling is a disappointment, the union's lack of success in federal court is completely separate from its state court suit.
"At the state level, the momentum currently is that there are two decisions that have declared right to work unconstitutional," he says.
The engineers union and the United Steelworkers union each filed lawsuits against right to work, saying it violates a provision of the Indiana constitution.
Both union suits have been successful at the county court level.
The engineers union's case will be heard by the state Supreme Court on Thursday.
Maher says his union hasn't decided whether to appeal in its federal case.