Rep. Darrell Issa is a leading critic of the lawsuit. The California Republican argues that the lawsuit interferes with the company's ability to decide where to do its work.
The NLRB alleges that Boeing violated labor laws by moving a new production line for its 787 airplane from Washington state to South Carolina. The agency claims Boeing is punishing workers for past strikes and wants the company to return the work to Washington.
Boeing denies the charges.
The NLRB has provided some documents to Issa, but says revealing other sensitive information would interfere with the case.