The National Collegiate Athletic Association is fighting a California bill that would let certain athletes to make money off their name, image or likeness, which NCAA officials and other traditionalists argue would undermine the “amateurism” of college sports.

NCAA President Mark Emmert sent a letter last week to the chairs of the two California State Assembly committees that vote on the Fair Pay to Play Act, USA Today first reported. The legislation already passed the State Senate in a 31-5 vote. It would permit athletes to be compensated if the college they attend earns an average of $10 million in media rights revenue a year.

At least 23 institutions in the state participate in Division I athletics, including four universities in the high-ranking Pacific-12 Conference.

The bill is the latest pressure the NCAA faces to rework its rules on athlete compensation on name, image or likeness. Pundits have accused the association and its member institutions of profiting off players while not sharing the wealth with them. The NCAA has maintained that paying athletes would push the college system too far into professional territory.

Emmert in his letter insinuated that California institutions both public and private would be barred from participating in NCAA championships.

“We recognize all of the efforts that have been undertaken to develop this bill in the context of complex issues related to the current collegiate model that have been the subject of litigation and much national debate,” Emmert wrote in his letter. “Nonetheless, when contrasted with current NCAA rules, as drafted the bill threatens to alter materially the principles of intercollegiate athletics and create local differences that would make it impossible to host fair national championships. As a result, it likely would have a negative impact on the exact student-athletes it intends to assist.”

Emmert asked that the committees postpone votes on the bill while the NCAA mulls its position on athletes making money from name, image or likeness. The NCAA last month formed a working group that will study that area of athlete compensation. The group members will make a final report to the association in October.

Emmert noted in his letter that though it wouldn’t take effect until 2023, “passage of the bill now will create confusion among prospective and current student-athletes and our membership.”

But the bill’s passage does seem likely. The Assembly’s Arts, Entertainment, Sports, Tourism and Internet Media Committee, one of the panels that Emmert wrote to, approved the legislation today in a 5-1 vote, with 1 member not voting and another absent. It is now due to be reviewed by the Higher Education Committee.

Though the Legislature is overwhelmingly liberal, the bill seems to have bipartisan support, as indicated by the Senate vote.

Washington Post sportswriter Sally Jenkins wrote in a blistering column that Emmert was bluffing and “California should call him out on it.”

“You really think Emmert is going to tell ESPN, CBS and Turner to take a hit in one of their biggest media markets, that the tournaments and bowl championships they paid billions of dollars in rights fees for will have to be played without the heart of the Pac-12?” Jenkins wrote. “‘Sorry, CBS, but you can’t have Stanford, Southern Cal, UCLA or Cal, because their kids might’ve made some cash from selling T-shirts with their own pictures on them.'”

The California State University system opposes the bill because it could result in its athletes being unable to compete, said Michael Uhlenkamp, spokesman with CSU’s Office of the Chancellor. Some athletes who may be ruled ineligible also would be on scholarship, which would take opportunities away from other players, Uhlenkamp said.

The University of California system is also against the bill. The NCAA did not respond to additional request for comment.

The bill also would forbid colleges from discontinuing or reducing athletes’ scholarships if they were also earning money from their name, image or likeness. If a player was seeking an agent, or other professional representation, that person would need to be licensed by the state, the bill stipulates.

Another measure challenging the NCAA rules was introduced recently by U.S. Rep. Mark Walker, a North Carolina Republican. This would strip the NCAA of its tax-exempt status if athletes were not allowed to profit off their name, image or likeness.

This debate around these issues intensified about a decade ago, after former University of California, Los Angeles, basketball star Ed O’Bannon sued the NCAA. O’Bannon — like many college athletes — was featured in an NCAA video game without giving his permission. He was successful in his antitrust lawsuit and secured a $40 million settlement with Electronic Arts, the video game publisher, that benefited tens of thousands of athletes who had appeared in games over the years.

The judge in that lawsuit, U.S. District Judge Claudia Wilken, envisioned a system in which colleges and universities put the athletes’ pay in trust accounts, wrote Michael McCann, a sports law expert and associate dean for academic affairs at the Franklin Pierce School of Law at the University of New Hampshire, in a column for Sports Illustrated.

McCann wrote if the NCAA did not win a court battle against the California bill, or decided to allow athletes to negotiate deals around name, image and likeness, their money could be placed in trusts that players could access after they leave college.

“Stated differently, while college athletes wouldn’t be paid for the use of their identity rights while they are in school, they would still earn from that use and be able to access those earnings after their time in college ends,” McCann wrote.