COLUMBIA, S.C. (AP) — A congressional committee is traveling to South Carolina later this month to hold a hearing over a federal labor lawsuit that claims Boeing Co. moved manufacturing facilities from Washington state to avoid unionized workers.

The U.S. House Committee on Oversight and Government planned to announce Wednesday that it will hold a June 17 hearing in North Charleston, home to Boeing's new 787 passenger aircraft assembly line.

In April, the National Labor Relations Board sued Boeing, claiming the manufacturer located its line in South Carolina — a right-to-work state — to retaliate against Washington state union workers who went on strike in 2008. The NLRB wants that work returned to Washington, even though the company has already built a new South Carolina plant and hired 1,000 workers.

Chairman Darrell Issa, R-Calif., has requested that NLRB Acting General Counsel Lafe Solomon attend the hearing, but Solomon wrote to Issa earlier this month that he wouldn't participate because of the ongoing litigation.

"Because my appearance at this hearing could threaten the rights of the parties to a fair trial, I must respectfully decline your invitation," Solomon wrote Issa on June 3."

In a letter dated Tuesday, Issa asked Solomon to reconsider that decision or face a possible subpoena compelling him to attend.

"This hearing will focus on how your actions against Boeing could impact the thousands of Boeing employees at a non-union worksite in South Carolina," Issa wrote Solomon. "You assert that you do not seek to close Boeing's operations in South Carolina, yet the relief requested would have that exact effect."

An NLRB spokeswoman did not immediately return a message seeking comment Wednesday.

Boeing said stopping 787 work in South Carolina would be impermissibly punitive because it would effectively shut it down and would be a radical departure from legal precedent. Last week, three employees at the North Charleston plant filed documents seeking roles in the NLRB lawsuit, saying they are sure to lose their jobs if the federal agency is successful and work on the 787 passenger jet returns to Washington state.

A hearing in the lawsuit is scheduled for June 14.