The shift to electric vehicles is looking better today for U.S. auto workers than it did before a strike against the three major Detroit automakers, thanks to agreements that expand the reach of the United Auto Workers to include battery manufacturing plants.

But the legacy of the strike—at least as it relates to EVs—will depend on the extent to which the United Auto Workers can use its gains from new contracts to build momentum in organizing nonunion plants, like those operated by Tesla, Honda and Toyota.

The union reached a tentative agreement with General Motors on Monday, which follows similar resolutions in recent days with Ford and Stellantis, the parent company of Chrysler. The UAW made several major gains, including provisions that will ease a path to unionization of workers at battery manufacturing plants, even if those plants are not wholly owned by the automakers.

The proposals, which end a strike that began on Sept. 15, still need to be ratified by members.

“We’ve said for months, ‘We refuse to allow the EV transition to become a race to the bottom,’” said UAW President Shawn Fain following the Ford agreement. “Corporate America is not going to force us to pick between good jobs and green jobs.”

EVs are only 8 percent of sales of new cars and light trucks in the United States, but their share is growing as manufacturers introduce waves of new models and as governments and consumers take steps to reduce carbon emissions. Transportation is the country’s leading source of emissions that contribute to climate change.

The Inflation Reduction Act has helped to supercharge investments in EV manufacturing. Much of the investment is at joint ventures between automakers and battery companies, and the UAW was seeking an opportunity to represent this fast-growing part of the automotive supply chain.

While the details vary for each automaker, the agreements either add battery plant workers to union contracts or have terms that create favorable conditions for workers unionizing at battery plants. For example, Ultium Cells, a battery manufacturing joint venture of GM and LG Energy Solution, would become part of the GM contract.

The Biden administration had said that it wants the jobs related to the transition to clean energy to be good ones, with livable wages and benefits. The IRA includes language to encourage this, using tax credits and other benefits.

Fain, who wore an “EAT THE RICH” T-shirt during one of his livestreams, was aggressive in his demands for higher pay and benefits.

And, as it became clear the strike was likely nearing an end, he spoke about what comes next, including organizing nonunion plants.

“We demanded a longer contract because one of our biggest goals coming out of this historic contract victory is to organize like we have never organized before,” he said. “When we return to the bargaining table in 2028, it won’t just be with the Big Three, but with the Big Five or Big Six.”

The Big Three are Ford, GM and Stellantis, companies with a history of operations in Michigan and of unionization.

They compete in a global market in which many of their rivals do not have unionized workforces. Toyota and Honda have operated nonunion plants in the United States since the 1970s, and Tesla has become the country’s EV leader with nonunion plants.

Some European automakers, like Volkswagen, have unionized plants in their home countries but have successfully resisted organizing efforts by the UAW in the United States.

The union had many advantages in this round of negotiations, said Aaron Sojourner, a labor economist at the W.E. Upjohn Institute for Employment Research in Michigan.

“The economy is strong, and the labor market is tight,” he said. “So employers don’t have a lot of leverage, and workers have more leverage.”

Also, the UAW has a favorable political environment with President Joe Biden, who walked on the picket line with workers.

But a strong contract can be harmful in the long run if it isn’t combined with the organizing of new plants at more companies and regions, Sojourner said. This is because the increase in labor costs at the affected plants could put them at a disadvantage.

“Strong contracts alone, without organizing, will just shrink the union,” he said.

Stephanie Brinley, an analyst for S&P Global Mobility, said Ford, GM and Stellantis can afford to make these agreements now in part because the economy is strong.

“It’s all good when everything’s going well,” she said. “In a downturn, it’s going to be difficult.”

About 10 percent of the country’s wage and salary workers were members of unions last year, down from a peak of 35 percent in the 1950s. The number of union members grew in 2022 compared to the prior year, although the unionized share of the work force declined a fraction of a percentage point because of substantial growth in the overall number of workers.

The UAW has felt the pain of the long-term decline, going from a peak of about 1.5 million members to a current total of less than 400,000 across the automotive, health care and higher education sectors, among others. It has about 146,000 members who are covered by contracts with the automakers.

The union now feels a sense of positive momentum. The GM agreement includes pay increases of about 25 percent through 2028, with top employees making $42 per hour and starting pay of about $30 per hour; the Ford and Stellantis contracts also have substantial pay raises. The agreement phases out some of the provisions of previous contracts that had a lower tier of wages for new employees.

“Like the agreements with Ford and Stellantis, the GM agreement has turned record profits into a record contract,” the UAW said on Monday.