A temporary order made by a court at the request of one party that prevents the other party from pursuing a particular course of conduct until the conclusion of a trial on the merits.
A preliminary injunction is regarded as extraordinary relief. The party against whom it is sought must receive notice and an opportunity to appear at a hearing to argue that the injunction should not be granted. A preliminary injunction should be granted only when the requesting party is highly likely to be successful in a trial on the merits and there is a substantial likelihood of irreparable harm unless the injunction is granted. If a party has shown only a limited probability of success, but has raised substantial and difficult questions worthy of additional inquiry, a court will grant a preliminary injunction only if the harm to him or her outweighs the injury to others if the injunction is denied.