Under the  National Labor Relations Act (NLRA), union stewards cannot be punished or  discriminated against because of their union activity, such as filing grievances  or speaking out on behalf of other workers.

Among other things, an employer may not:

• Order a steward to perform extra or more difficult work
• Deny a steward pay opportunities
• Isolate a steward from other workers
• Deprive a steward of overtime
• Enforce rules more strictly against a steward
• Overly supervise a steward