NASCAR has long been a predominantly white sport. Now a lawsuit is trying to prove that’s intentional.

On Sept. 16, Diversity Motorsports Racing sued the National Association for Stock Car Auto Racing (NASCAR) for $500 million, claiming the sport prevents black-owned teams and drivers from competing. Diversity Motorsports Racing is also asking the court to require the defendants to “fully integrate the African-American community.” The case was filed in Manhattan’s U.S. district court.

The lawsuit argues NASCAR and its teams have “engaged in unlawful intentional racial discrimination by refusing to sanction African-American owned racing teams,” as well as “refusing to hire African-American drivers for its racing teams.”

In a statement, NASCAR responded, “Diversity both on and off the track continues to be a top priority for NASCAR and its stakeholders. We stand behind our actions, and will not let a publicity-seeking legal action deter us from our mission.”

Terrance Cox, the co-founder of Diversity Motorsports—a stock car racing team devoted to driver diversity—is also the founder of Minority Youth Matters Movement, a national campaign of protests at NASCAR events, which started last September. “Our goal is to design, develop, and manage a program sponsored by interested corporations to meet diversity and inclusion milestones within the sport,” MYMM wrote in the campaign’s announcement.

In NASCAR’s 68-year history, only three black drivers have ever competed in the sport’s top series, now known as Sprint Cup. When Darrell Wallace Jr., who currently drives a Ford Mustang for Roush Fenway Racing in the NASCAR Xfinity Series (the second-tier league), won a 2013 Camping World Truck Series (the third-tier league) race in Virginia, he became the first black driver to win a race on any of the sport’s top three national levels since Wendell Scott took first in a Cup race in 1963. NASCAR’s own diversity program produced recent Cup race-winner Kyle Larson, who is of Japanese-American heritage.