The legal fight over whether former NFL players can return to college football is escalating, with the Southeastern Conference filing a lawsuit Thursday against LSU and head football coach Lane Kiffin.

The lawsuit also names LSU’s Board of Supervisors and comes amid a dispute over eligibility rules for athletes who previously played professionally.

The SEC alleges LSU is recruiting players who signed NFL contracts with the Cleveland Browns, New Orleans Saints and Tampa Bay Buccaneers. The Associated Press identifies the players as Zxavian Harris, Dae’Quan Wright and Blake Cotton.

The lawsuit comes after Georgia Attorney General Chris Carr sent a letter Wednesday to SEC Commissioner Greg Sankey asking the conference to take “all measures available” to stop LSU from adding former NFL players to its roster.

Louisiana Attorney General Liz Murrill has filed a brief supporting the athletes.

“These players are seeking a fair forum to have their grievances heard and I think they deserve that,” Murrill said.