Boeing supplier Spirit AeroSystems will furlough some 700 workers as a strike by machinists at the plane maker enters its sixth week, a spokesman for the supplier said Friday.

Spirit AeroSystems Holdings Inc. will start furloughing workers later this month in response to the continuing strike at Boeing Co., the aerostructure supplier’s biggest customer.

Spirit AeroSystems will furlough 700 employees in Wichita for 21 days starting Oct. 28, the company said Friday. The furloughs will affect employees working on the Boeing 767 and 777. The furlough is a result of the ongoing strike by Boeing employees, which started on Sept. 13.

As the Boeing Company (NYSE:BA) strike drags on, Spirit Aerosystems Holdings, Inc. (NYSE:SPR) faces tough choices ahead, including the looming threat of layoffs and extended furloughs. On Friday, Spirit Aerosystems announced employee furloughs in response to the ongoing strike by Boeing workers represented by the International Association of Machinists and Aerospace Workers,

Boeing factory workers held a large rally in Seattle to demand a better wage deal, mounting pressure on new CEO Kelly Ortberg to end a bitter strike that has plunged the planemaker further into financial crisis.

The aerostructures supplier is sending home 700 workers on its 767 and 777 fuselage programmes, as a machinists strike at partner Boeing has hobbled aircraft production.

Spirit AeroSystems says it plans to soon start a 21-day furlough for hundreds of workers supporting Boeing’s 777 and 767 jetliner programs.

Around 700 Spirit AeroSystems employees are being furloughed as a result of the ongoing strike by Boeing machinists that began last month, the company announced Friday.