O.C.G.A. § 5-6-1: Appearance before court of interested third parties.

When a case is set for a hearing before the Supreme Court or the Court of Appeals and there are parties besides the plaintiffs and defendants, whether shown by the record or not, who have a direct interest in its result, upon the interest being made to appear the court shall allow the other parties to appear by counsel on equal terms with the parties directly before the court.