Compare with inter partes.
Ex parte refers to those proceedings where one of the parties has not received notice and, therefore, is neither present nor represented.
If a person received notice of a hearing and chose not to attend, then the hearing would not be called ex parte.
Some jurisdictions expand the definition to include any proceeding that goes undefended, even though proper notice has been given.
In Lazard Bros. & Co. v. Banque Industrielle de Moscou, Justice Scrutton wrote:
"Persons applying ex parte to the Court must use the utmost good faith, and if they do not, they cannot keep the results of their application."
In Cheng v Cheng, Justice Cirillo of the Supreme Court of Pennsylvania iterated the classic statement of ex parte:
"A judicial proceeding is "ex parte" if one party applies to the court for and is awarded relief without the presence or even the knowledge of the other party, who may be affected or bound by the proceeding without having had his or her constitutionally protected opportunity to appear and be heard."
There is some elasticity to what is ex parte. In Re Anonymous, communication was at issue:
"... by seeking emergency relief without providing notice and without certifying to the judge what efforts, if any, the respondent had made to give notice or the reasons why notice should not be required, the respondent engaged in an impermissible ex parte contact with the court."
Similarly, in Anchor Packing v Grimshaw:
"Ex parte communication is a communication about a case that an adversary makes to the decision maker without notice to an affected party. A judicial proceeding, order, or injunction is said to be ex parte when it is taken or granted at the instance and for the benefit of one party only and without notice to or contestation by, any person adversely interested."
In Matter of Endicott, Justice Glen Williams of the United States District Court went even further:
"A written communication between the trustee and the bankruptcy judge is considered to be ex parte if an opposing party does not timely receive a copy of the submitted document."
Injunctions is an area where ex parte applications are often sought. Note these comments adopted by Justice Schulman of the Manitoba Court of Appeal in his reasons in Dakota v Woods, and which apply in all cases where ex parte relief is sought:
"It is a well-established principle of our law that a party who seeks the extraordinary relief of an ex parte injunction must make full and frank disclosure of the case. The rationale for this rule is obvious. The judge hearing an ex parte motion and the absent party are literally at the mercy of the party seeking injunctive relief. The ordinary checks and balances of the adversary system are not operative. The opposite party is deprived of the opportunity to challenge the factual and legal contentions advanced by the moving party in support of the injunction. The situation is rife with the danger than an injustice will be done to the absent party....
"There is no situation more fraught with potential injustice and abuse of the Court’s powers than an application for an ex parte injunction. For that reason, the law imposes an exceptional duty on the party who seeks ex parte relief. That party is not entitled to present only its side of the case in the best possible light, as it would if the other side were present. Rather, it is incumbent on the moving party to make a balanced presentation of the facts and law. The moving party must state its own case fairly and must inform the court of any points of fact or law known to it which favour the other side. The duty of full and frank disclosure is required to mitigate the obvious risk of injustice inherent in any situation where a judge is asked to grant an order without hearing from the other side.
"If the party seeking ex parte relief fails to abide by this duty to make full and frank disclosure by omitting or misrepresenting material facts, the opposite party is entitled to have the injunction set aside. That is the price the plaintiff must pay for failure to live up to the duty imposed by the law. Were it otherwise, the duty would be empty and the law would be powerless to protect the absent party.
"However, inflexible application of this rule is to be avoided and failure to make full disclosure is not invariably fatal. Ex parte applications are, of necessity, brought on an urgent basis with little time to prepare supporting materials. Orders should not be set aside on account of mere imperfections in the affidavits or because inconsequential facts have not been disclosed."