Opponents of a campus gun ban at the University of Colorado told the state Supreme Court on Wednesday the gun ban is illegal because it was not banned by the legislature.

The Colorado Court of Appeals in April ruled in favor of a gun-rights group that sued the University of Colorado, arguing that a 1994 university policy banning concealed weapons violates state gun laws.

CU left its concealed weapons ban in place. In June, the school’s Board of Regents decided to fight the appellate court’s decision.

Supporters told the court that the issue is not whether guns should be allowed on campus, but whether the Board of Regents has the power to set school policies.