On Friday morning, thousands of workers walked out of the so-called Big Three automakers’ US plants to commence the United Auto Workers’ strike – believed to be the industry’s biggest action in generations.

Detroit-based General Motors, Ford and Stellantis have failed to secure a union contract deal with the UAW before midnight, leading autoworkers in Ohio, Missouri and Michigan to walk off the job. Plants impacted Friday include the Stellantis Toledo Assembly Complex, GM Wentzville Assembly and the Ford Michigan Assembly Plant.

Roughly 12,700 workers were included on the first day of the strike, though 145,000 UAW members work at the Big Three. While some members are now under an expired contract, not all workers will be asked to strike initially.

UAW president Shawn Fain noted in a Facebook live address that this is the first time the UAW has conducted a simultaneous strike of the Detroit automakers, though he added that company-wide strikes are still on the backburner.

However, Stellantis – which makes vehicles under brands like Chrysler and Jeep – said in a statement Friday that it has already entered “contingency mode” and would make structural decisions to protect itself as it sees fit.

Among other contract demands, the UAW is requesting a 36% wage increase over four years, better benefits and more job protections. These additional costs could put pressure on EV manufacturers and raise vehicle prices, as could a long-term strike, Kallanish notes.

On Friday evening, the UAW was still advising certain workers to continue working under an expired contract. However, If the Big Three cannot reach a timely agreement with the union, shutdowns could spread to other facilities, such as GM’s EV-focused Factory Zero in Hamtramck, Michigan.

Automakers have already faced several EV-related difficulties this year. In July, Ford said it would delay its EV production timeline due to slowed demand, now expecting a production rate of 600,000 EVs a year in 2024, rather than 2023. In the same month, GM said its EV rollout had been delayed due to production troubles with the Ultium battery pack.

Some battery workers are also unionising with the UAW, according to NPR, though on separate contracts. The UAW previously raised concerns around EV manufacturing and battery sourcing, noting on its website in 2021 that “the EV transition should not result in increased outsourcing or erosion of job quality in the industry.”