Here, an important public interest is at stake -- the validity of an Act of Congress having far-reaching effects on the public welfare in one of the most critical periods in the history of the country. That interest has been adjudicated in a proceeding in which the plaintiff has had no active participation, over which he has exercised no control, and the expense of which he has not borne. He has been only nominally represented by counsel who was selected by appellee's counsel and whom he has never seen. Such a suit is collusive because it is not in any real sense adversary. It does not assume the "honest and actual antagonistic assertion of rights" to be adjudicated -- a safeguard essential to the integrity of the judicial process, and one which we have held to be indispensable to adjudication of constitutional questions by this Court. Chicago & Grand Trunk Ry. Co. v. Wellman, 143 U. S. 339, 143 U. S. 345, and see 49 U. S. 134-135;Atherton Mills v. Johnston,@ 259 U. S. 13, 259 U. S. 15. Whenever, in the course of litigation, such a defect in the proceedings is brought to the court's attention, it may set aside any adjudication thus procured and dismiss the cause without entering judgment on the merits. It is the court's duty to do so where, as here, the public interest has been placed at hazard by the amenities of parties to a suit conducted under the domination of only one of them. The district court should have granted the Government's motion to dismiss the suit as collusive.
US v Johnson, 319 US 302 (1943)