A judge has denied a request by three Boeing workers seeking to formally join and fight a labor lawsuit the company is facing, a group representing the employees said today.

The National Right to Work Legal Defense Foundation said it would immediately appeal the ruling, which was handed down by a San Francisco judge from the National Labor Relations Board.

The NLRB also is the agency that’s suing Boeing. Its complaint alleges that the company’s 2009 decision to build a secondary 787 aircraft assembly line in North Charleston was an illegal form of retaliation against the International Association of Machinists & Aerospace Workers for previous strikes in Washington state.

The labor board’s acting general counsel, Lafe Solomon, is seeking an order that would force the company to move the South Carolina assembly line to the Puget Sound area.

Earlier this month, Boeing employees Dennis Murray, Cynthia Ramaker and Meredith Going Sr. filed a request to participate in the lawsuit, partly because they were concerned about the impact of the case on their jobs.

They are being represented by the National Right to Work Legal Defense Foundation.

The NLRB opposed their participation, saying their involvement “would merely delay and complicate these already complex proceedings.”

The first hearing in the labor lawsuit is scheduled for Tuesday in Seattle. Boeing plans to mark the completion of its new North Charleston plant at a ceremony tomorrow.