Members of the United Automobile Workers union have thrown their support behind new contracts with the Big Three American automakers, deals that deliver steep wage increases and other gains that had eluded the union for more than 20 years.

In the closest vote, General Motors’ tentative contract agreement won the support of 55 percent of the nearly 36,000 members who voted, according to a count of all GM locations which the union published on Thursday.

Tentative agreements with Ford engine and stellantisthe maker of brands like Jeep and Chrysler, seemed headed for approval by more decisive margins, almost complete results showed.

A union spokesman confirmed the accuracy of the counts but declined to comment further.

The agreements are similar among the three automakers and increase the maximum wage for production workers by 25 percent, to more than $40 in four and a half years, from $32. They were reached last month after a six-week wave of strikes that paralyzed companies, a strategy spearheaded by the union’s new president, Shawn Fain, who had promised to take a more confrontational approach to negotiations than his predecessors.

The agreements appear to have quickly reverberated throughout the auto industry, with Toyota, Hyundai and Honda announcing significant pay increases at non-union plants in the United States just days later.

“We call that the UAW surge, and it means ‘You’re welcome,'” Fain said in testimony before the Senate Health, Education, Labor and Pensions Committee this week. “And we are very proud of it. And when these workers decide to organize and join the UAW, they will reap all the benefits of union membership and get everything they are entitled to.”

The new contracts also included increased company contributions to workers’ retirement plans and the right to strike over plant closures. The three automakers declined to comment on the ratification votes.

Fain said the union was trying to capitalize on its momentum by carrying out strong organizing drives at non-union plants and, in comments presented to the Senate committee, he added that thousands of workers were already contacting the union and signing union cards.

But even Fain’s tough approach in talks with the Big Three did not produce terms attractive enough to many union members. GM workers at several large plants voted against the tentative deal by wide margins.

In contrast, members of the International Brotherhood of Teamsters recently approved a new contract with United Parcel Service with 86 percent support, while a new contract between the Writers Guild of America and Hollywood studios was approved with 99 percent. percent support.

Rebecca Givan, a professor of labor studies at Rutgers University, said Fain had achieved a big victory despite having taken office only months earlier with the goal of reorienting the union.

Dr. Givan said the union’s approach of striking initially at one plant at each of the three automakers and escalating it over time had “really upended a lot of the conventional wisdom” in the labor movement and had proven to be unusually successful in reversing some concessions the union had made. had accepted years earlier, such as the suspension of a cost-of-living adjustment.

“This shows that if workers build enough power, they can take things back,” he said.

UAW members at Mack Truck too ratified a contract on Wednesday, after rejecting an initial agreement with the company.

At all three automakers, skepticism toward the deals largely arose from veteran workers who felt the proposed contracts did not go far enough to compensate them for years of concessions and weak wage growth, even taking into account strong gains for newer workers. Salaries for some new workers will more than double over the next four years.

Huey Harris, a GM employee at a large truck assembly plant in Flint, Michigan, who has worked at the company for more than 20 years, said the deal should have gone further in rewarding veteran workers, although finally voted in favor. “Traditional people didn’t think they were offered enough in the contract,” he said.

Several former employees of the Big Three automakers said that even after the big profits from the new contract, they would not earn more than when they began their careers.

Curtis March, who works at Ford’s Chicago assembly plant, said he earned about $18 an hour once he reached the top wage for the company’s production workers in the early 1990s, equivalent to more of 40 current dollars if adjusted for inflation. He will earn about $36 in the first year of the new contract.

March said Ford was likely to approve the deal because it appeased newer employees, who outnumber veterans like him. Workers at its plant approved the deal after voting against several previous contracts.

Despite the ultimate success, the path to ratification of the contracts has included some internal tensions for Fain and the union. Unite All Workers for Democracy, a reform group that played a key role in electing Fain and six other UAW executive board members to their positions, declined to formally recommend that union members approve the contract even after it Fain urged the group. do so at a recent meeting, according to three people familiar with the meeting. Instead, Unite All Workers approved a resolution pledging to remain neutral during the ratification vote, although stating that the group “celebrates the record achievements made in this agreement.”

Two of these people also said that the union’s General Motors department had been less communicative and less proactive in distributing information about the contract to local union officials and members than the Ford and Stellantis departments.

The union declined to comment on these developments.

Ratification could also bring political benefits to President Biden, who intervened in negotiations over the summer and fall, and who risked angering business leaders by increasingly siding with union members.

Administration officials were taken aback in August when Fain called for a 40 percent raise for auto workers and a four-day work week. Executives from the Big Three called the White House to ask if Fain was serious. A senior administration official said Biden advisers had assured them that the union wanted a deal, but acknowledged that negotiations could be very different from what automakers were used to.

In mid-September, when Biden was in New York for meetings at the United Nations General Assembly, he joined aides on a video call to make a decision he and his team had been working on for weeks: join to auto workers on a picket line in Detroit. That decision infuriated executives, the administration official said, but the White House saw it as a victory for the president and workers, making a clear statement about Biden’s position in the negotiations.

Some autoworkers argued that the union had made a mistake by not expanding the strike, which eventually included about a third of unionized company workers in the United States, and even more.

LaDonna Newman, another longtime Ford worker who opposed the contract because of its limited benefits for veteran workers, said she believed the union could have won more at the bargaining table if it had been willing to escalate further.

Still, he did not blame Mr. Fain for the outcome. “He walked into a burning building,” Newman said. “I congratulate you very much for having the courage to go against the corporations.”

Jim Tankersley and Sofia Lada contributed with reports.