As the U.S. Women’s National Soccer team marches towards the 2019 FIFA World Cup final on Sunday, the battle over equal pay rages on. Now the women, who make about 38 percent of what players on the men’s team do, have members of Congress calling on the U.S. Soccer Federation to make changes.

The House Democratic Women’s Caucus wants U.S. Soccer to come up with a plan to “address institutionalized gender discrimination” and send them official documents detailing the salary, bonuses and prize money for the women’s and men’s national teams.

“The inequities that these women champions have faced as members of the USWNT are indefensible,” the members wrote Wednesday in a letter to President Carlos Cordeiro. “The U.S. Soccer Federation should work to correct course and close the wage gap so that the only thing women athletes are fighting for is the world title or a gold medal.”

The group argues that the pay disparity sends a message to “women and girls is that their skills and accomplishments are of lesser value” — and could potentially violate the Amateur Sports Act of 1978, which requires governing bodies to offer equal support to women.

Despite a No. 1 world ranking and three World Cup titles (1991, 1999 and 2015), the women’s team received just $1.725 million for winning in 2015, or about one-third of what U.S. soccer gave the men for going out in the round of 16 in the 2014 World Cup, according to the letter.

This 2019 team has been one of the most heavily scrutinized in recent memory. Some scolded players for celebrating “excessively” during the opening round 13-0 rout of Thailand. Others criticized co-captain Megan Rapinoe for insisting there’s no way she’s “going to the f—ing White House” should the team win the World Cup, or reproached the team for its brashness in the equal pay fight, as players suing the federation tentatively agreed to enter mediation.

The timing of the equal pay push couldn’t be better. Coming off a dominant 2015 World Cup title run and a possible 2019 repeat, the women’s team would seem to have its strongest argument.

It also doesn’t hurt that the women’s team is eclipsing the men in popularity and in revenue generation. For instance, between 2016 and 2018, the women generated $50.8 million while the men made $49.9 million. Meanwhile, the 2015 Women’s World Cup final was the most watched soccer match in U.S. history, while the men failed to even qualify for the 2018 World Cup.

More than 50 members of Congress signed Wednesday’s letter, including Democratic Women’s Caucus Co-Chairs Jackie Speier of California, Lois Frankel of Florida and Brenda L. Lawrence of Michigan.