A gender discrimination class action against the U.S. Soccer Federation kicks to the courts a long-simmering conflict over pay disparities in the professional sport, just as a venue fight flares in a related case.

The class action, filed three months before the FIFA Women's World Cup, alleges that the U.S. Soccer Federation pays members of the U.S. Women's National Team less than their male counterparts. The lawsuit was filed March 8 by 28 team members under Title VII of the Civil Rights Act and the Equal Pay Act, which requires class members to opt into the case, brought on behalf of current and former team members starting in 2015.

The case caps a lengthy feud between the U.S. Soccer Federation and the women's soccer team, winner of the Women's World Cup in 2015 and ranked No. 1 in the world. On Aug. 24, former goalkeeper Hope Solo filed her own suit against the U.S. Soccer Federation for the same claims.

“The women, starting in 2004, have always asked for equal pay,” said Solo's attorney, Richard Nichols, who was executive director and general counsel of the U.S. Women's National Soccer Team Players Association, which negotiates for the team's collective bargaining agreement, in 2015 and 2016. “U.S. Soccer has said no.”

Solo and four other players filed a discrimination charge in 2016 with the U.S. Equal Employment Opportunity Commission. The class action includes the other four women, who received notices of right to sue from the EEOC last month.

The suit, filed by Jeffrey Kessler, the same attorney who represented the women in the EEOC charge, comes as the U.S. Soccer Federation has moved to transfer Solo's case from California to Illinois, where its headquarters are in Chicago. A federal judge in San Francisco heard arguments on that motion last month.

Nichols, a solo practitioner in Novato, California, said he did not want his case in Illinois, where the U.S. Soccer Federation won a declaratory judgment against the women's players union in 2016 when the team threatened to go on strike just before the Olympics.

“Given that experience,” he said, “I would feel a lot better if this case was not adjudicated in Chicago.”

He conceded that the U.S. Soccer Federation's connections in California are mostly in Los Angeles, home to its national training camp. Los Angeles also is where attorney Kessler filed the class action. On March 8, Kessler, co-executive chairman of Winston & Strawn in New York, brought a motion to coordinate his case with Solo's lawsuit into a multidistrict litigation proceeding in Los Angeles, citing a “strong nexus” to the case.

Solo's case provides a glimpse into the U.S. Soccer Federation's possible legal defenses in the class action. In a Dec. 31 motion to dismiss Solo's case, the federation argued that compensation to players of the two teams were different: women receive a salary, while men's payments are per game. And each operated under separate collective bargaining agreements.

The Equal Pay Act applies to discrimination against women who work at the same “establishment” as men in jobs involving “substantially equal skill, effort and responsibility.”

“This is not a case where employees are working side-by-side, doing the exact same job, but getting paid differently for the same work,” wrote Ellen McLaughlin, a partner at Seyfarth Shaw in Chicago, who heads an all-women's legal team for the federation in the case. “Rather, this case takes two entirely different categories of professional athletes—athletes who play for different teams, have different obligations, are compensated in fundamentally different ways, and enjoy different benefits—and asks the court to conclude that they are suitable comparators for each other under the EPA.”

McLaughlin did not respond to a request for comment.

Nichols called that a “ridiculous argument.”

“U.S. Soccer is the single employer of the men's and women's teams,” he said. “The men and women do the same job under similar circumstances in similar venues under the same rules and regulations depicted by their employer, U.S. Soccer. There are no two separate establishments.”

As to the salary difference, he said, women had argued before for a pay-to-play system like that of male players, who get between $5,000 to $17,625 per game, but the federation wouldn't guarantee a number of games each year.

“Women needed to make sure they needed to make some money playing for the United States, and the only way to do that, for a guaranteed income, was to have a salary,” he said.