Preliminary Injunction Definition

A court order early in a lawsuit that prohibits the parties from taking a disputed action until the court can decide the merits of the case. For example, if a lawsuit is filed challenging the validity of a new government regulation, the court might issue a preliminary injunction preventing the government from enforcing the regulation until the court can decide whether the regulation is valid. Generally, the party seeking a preliminary injunction must show a substantial likelihood of success on the merits of the lawsuit and a substantial threat of irreparable harm if the injunction is not granted.