(DETROIT) — The head of the United Auto Workers said plans by two automakers to temporarily lay off non-striking employees “won’t work,” as the unprecedented strike enters the second day.

The UAW, which represents nearly 150,000 autoworkers, started a strike early Friday morning against the Big Three automakers — General Motors, Ford and Stellantis. Nearly 13,000 workers walked out of three auto plants in Michigan, Missouri and Ohio. The union is utilizing a “stand-up” strike method to target specific plants and add to the list if a deal isn’t reached.

Hours after the strike started, Ford announced it told 600 workers who assemble cars at a plant in Michigan not to report to work that day, citing the “knock-on effects” of the strike. Workers in the paint department at a nearby plant are out on strike, leaving the assembly workers without adequate parts, since the parts require paint before they can be put together into cars, the company said in a statement to ABC News.

“Our production system is highly interconnected, which means the UAW’s targeted strike strategy will have knock-on effects for facilities that are not directly targeted for a work stoppage,” Ford said.

GM also said on Friday it plans to idle 2,000 workers at its Fairfax assembly plant in Kansas as soon as early next week due to a “ripple effect” of the strike at its Wentzville assembly plant in Missouri. The strike will mean a shortage of “critical stampings” supplied by Wentzville to Fairfax, GM said.

“We have said repeatedly that nobody wins in a strike, and that effects go well beyond our employees on the plant floor and negatively impact our customers, suppliers and the communities where we do business,” GM said in a statement. “What happened to our Fairfax team members is a clear and immediate demonstration of that fact.”

Stellantis has not announced any plans to lay off workers amid the strikes.

UAW president Shawn Fain responded to the announcements on Saturday.

“Let’s be clear: if the Big Three decide to lay people off who aren’t on strike, that’s them trying to put the squeeze on our members to settle for less,” Fain said in a statement. “With their record profits, they don’t have to lay off a single employee. In fact, they could double every autoworker’s pay, not raise car prices, and still rake in billions of dollars.”

“Their plan won’t work,” the statement continued. “The UAW will make sure any worker laid off in the Big Three’s latest attack will not go without an income. We’ll organize one day longer than they can and go the distance to win economic and social justice at the Big Three.”

A UAW source told ABC News on Saturday afternoon the union had “reasonably productive conversations with Ford today.”

Economists previously told ABC News a strike could result in billions of dollars in losses, disruption to the supply chain and other financial consequences.

Sticking points in negotiations were wage increases and the length of the workweek.

President Joe Biden said Friday he is deploying acting Labor Secretary Julie Su and White House senior adviser Gene Sperling to Detroit to offer their support for the parties in reaching an agreement.

ABC News’ Alexandra Hutzler contributed to this report.

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