TALLAHASSEE, Fla. – A more than year-long legal battle between Florida State University and the Atlantic Coast Conference continued to ratchet up Monday, with the conference turning to the Florida Supreme Court to try to halt a lawsuit filed by FSU.

Attorneys for the conference filed a brief urging the Supreme Court to review a November decision by the 1st District Court of Appeal that rejected a stay of the FSU lawsuit. The conference also filed a separate motion asking justices to prevent a circuit judge from moving forward with the lawsuit while the Supreme Court considers the stay request.

The filings stem from dueling lawsuits that the conference and FSU filed in December 2023 about sports media rights — and a widespread belief that FSU wanted to leave the conference.

The conference filed its lawsuit in North Carolina, where it is based, one day before FSU filed its lawsuit in Leon County. As a result of the North Carolina case being filed first, the conference argues that it should be decided before the Leon County case, a legal concept known as the “principle of priority.”

But Leon County Circuit Judge John Cooper and a panel of the 1st District Court of Appeal last year rejected the conference’s arguments about a stay and the principle of priority.

In its brief Monday asking the Supreme Court to take up the issue, the conference painted the issues in sweeping terms.

“The First District’s decision, which abrogates the principle of priority and sets North Carolina and Florida on a jurisdictional collision course, may present the most important federalism issue that any member of this (Supreme) Court has, to date, had the privilege to consider,” wrote the ACC’s attorneys, who include former Florida Supreme Court Justice Alan Lawson. “Contrary to decades of precedent, the decision undermines Florida’s role in our federal constitutional order and the stability and predictability of our law in ways that will profoundly destabilize our justice system if not corrected.”

Cooper ruled that the principle of priority should not apply, in part, because the ACC’s lawsuit in North Carolina was an “anticipatory filing” that the conference made after finding out the university planned to file a lawsuit in Florida. As a result, he said a stay was not justified. The three-judge panel of the 1st District Court of Appeal upheld Cooper’s ruling.

FSU has essentially contended in the legal battle that the ACC has shortchanged its members through television contracts and that the school would face exorbitant financial penalties if it leaves. But the ACC has argued that the university entered a contract that granted media rights to the conference.

The university sought dismissal of the conference’s North Carolina lawsuit or, as an alternative, a stay. But Louis Bledsoe, chief business court judge in Mecklenburg County, N.C., rejected FSU’s requests in April.

In denying the stay, Bledsoe wrote that the “ACC did not engage in improper conduct or ‘procedural fencing’ in filing this action in North Carolina. Accordingly, considering all of the facts and circumstances surrounding the filing of this action and the Florida action, the court concludes, in the exercise of its discretion, that the ACC’s choice of forum is entitled to deference on this record.”

FSU appealed Bledsoe’s ruling, and the case is pending at the North Carolina Supreme Court, according to Monday’s filings in Florida.