Fitch Ratings and Moody’s have joined S&P Global Ratings in warning that a prolonged strike at Boeing’s factories on the United States West Coast may lead to a ratings downgrade, a headache for the plane maker, which is saddled with massive debt.

“If the current strike lasts a week or two, it is unlikely to pressure the rating. However, an extended strike could have a meaningful operational and financial impact, increasing the risk of a downgrade,” Fitch said on Friday.

Moody’s warned of a downgrade if Boeing issues debt alongside any equity raised to meet its liquidity requirements, including the money it needs to retire about $12bn of debt maturities from now to the end of 2026.

Moody’s currently rates the aircraft maker at “Baa3” while Fitch has a “BBB-” rating — both a notch above junk status.

More than 30,000 workers walked off their jobs at Boeing on Friday after rejecting a proposed contract, halting production of its 737 MAX jet, the company’s main cash cow.

Chief Financial Officer Brian West did not directly answer when asked if Boeing may need to raise debt or equity by year’s end or early 2025.

“First of all, we want to prioritise the investment grade credit rating. And secondly, we want to allow the factory and the supply chain to stabilise. That last objective just got harder based on last night,” he said at a conference organised by Morgan Stanley, referring to the workers’ vote on Thursday to strike.

“We are perfectly comfortable to supplement our liquidity position to support these two objectives,” West said.

The first labour strike at Boeing since 2008 coincides with a period of intense scrutiny of the plane maker by US regulators and airline customers after an incident in January when a door panel detached from a 737 MAX jet midair.

Boeing’s management will likely need to access new sources of liquidity in the event of a prolonged strike to adhere to its cash targets and to remain within Fitch’s negative rating sensitivity, the ratings agency said.

S&P Global Ratings had said on Thursday that an extended strike could delay the plane maker’s recovery and hurt its overall rating.

Boeing’s finances are already groaning due to a $60bn debt pile.

Shares of the plane maker were down 4 percent in Friday afternoon trading, touching an 18-month low.