The company’s largest union rejected a contract that called for a 25% pay increase, dealing a financial blow when the plane maker is bleeding cash.

Boeing's U.S. West Coast factory workers walked off the job early on Friday after overwhelmingly rejecting a contract deal, halting production of the planemaker's strongest-selling jet as it wrestles with severe output delays and heavy debt.

More than 30,000 Boeing workers have begun a strike to demand higher wages and improved pensions. Union leader Jon Holden stated that the workers, producing key aircraft models like the 737 MAX, are prepared for a protracted dispute until their demands are met.