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.

More than 32,000 Boeing workers walked off the job Sept. 13 after overwhelmingly rejecting a tentative labor deal with Boeing, deepening the aircraft producer’s financial strain and handing a new challenge to CEO Kelly Ortberg, who took the reins just over two months ago.

The temporary furloughs account for about 5% of Spirit’s U.S. workforce, according to its latest annual filing.

The temporary furloughs will affect employees at Spirit’s largest facilities, in Wichita, Kansas, and account for about 5% of Spirit’s U.S. workforce, according to its latest annual filing. Meanwhile, Boeing and its machinists’ union remain at an impasse, and Spirit is considering deeper cuts.

“If the strike continues beyond November, we will have to implement layoffs and additional furloughs,” Spirit spokesman Joe Buccino told CNBC on Friday.

Ortberg, who faces investors in his first earnings call next Wednesday, last week announced a series of drastic measures meant to slash costs as the company’s losses mount, including cutting the workforce by 10%, or about 17,000 people. Boeing is also ending 767 commercial production when orders are fulfilled in 2027 and said its long-delayed 777X wide-body jet won’t debut until 2026, pushing it back yet another year.

Boeing is in the process of raising debt or equity to increase liquidity.

The roughly 700 Spirit workers affected by the 21-day furlough are assigned to the 777 and 767 programs for Boeing, for which Spirit has built up “significant inventory,” Buccino said. Spirit workers on Boeing’s bestselling 737 Max are not affected, he added. Work on all three programs, however, is stalled because of the strike.

Boeing agreed to acquire Spirit this summer, but the companies don’t expect the deal to close until mid-2025. Reuters earlier reported Spirit’s latest furloughs.

It’s been just over a month since more than 30,000 Boeing machinists walked off the job after overwhelmingly voting down a tentative contract. Costs and tensions have only risen since then.

The strike is adding to pressure on Boeing’s new CEO, Kelly Ortberg, who was brought in over the summer to solve the plane maker’s various troubles. The strike, which S&P Global Ratings estimates costs Boeing more than $1 billion a month, bookends an already difficult year that started with a near-catastrophic blowout of a 737 Max door plug and comes six years after the first of two fatal Max crashes put the storied manufacturer in constant crisis mode.

The union and company remain at an impasse, and airplane production at factories in the Seattle area and other locations has been idled, depriving Boeing of cash. Boeing last week pulled a sweetened contract offer that the union had rejected, saying it wasn’t negotiated.

Boeing officials had been upbeat to airline customers about getting to a deal in the weeks before the original vote, according to people familiar with the matter who spoke on the condition of anonymity because the conversations were private.

But that optimism didn’t pan out, as workers on Sept. 13 voted 95% against an initial tentative labor deal.

“They’ll have to increase their offer. There’s no doubt about that,” said Harry Katz, a professor who studies collective bargaining at Cornell University’s School of Industrial and Labor Relations. He said one of the union’s demands, a return to a pension plan, is unlikely, however, and estimated the strike could last two to five more weeks.

The process of ending strike has turned more fraught, with federally mediated talks breaking down midweek.

Boeing on Thursday said it filed an unfair labor practice charge with the National Labor Relations Board that accused the International Association of Machinists and Aerospace Workers union of negotiating in bad faith and misrepresenting the plane makers’ proposals.

Late Friday, Jon Holden, president of the striking workers’ union, IAM District 751, pushed for a return to negotiations.

“CEO Ortberg has an opportunity to do things differently instead of the same old tired labor relations threats used to intimidate and crush anyone that stands up to them,” he said in a statement. “Ultimately, it will be our membership that determines whether any negotiated contract offer is accepted. They want a resolution that is negotiated and addresses their needs.”

Boeing’s unionized machinists are not receiving paychecks and lost their company-backed health insurance at the end of September. However, unlike during the last Boeing factory strike in 2008, there is more contract work in the Seattle area to help workers fill the gaps. A union message board posts job opportunities like driving for food delivery services and warehouse work.