Judicial review is a form of supervision that a court exercises over an administrative decision-maker. It differs from an appeal or the exercise of judicial authority in the course of a trial. It is limited in its scope. Often, according to the latest jurisprudence from the Supreme Court of Canada, it is intended only to disturb decisions by administrative decision-makers if they are unreasonable, which is a different standard from asking whether the decision is correct or incorrect.
There is something unique in immigration law in Canada. In all other areas of law, one gets to seek judicial review, to go to the court and ask it to supervise the decision of the administrative decision-maker on request. In immigration law, you have to get permission of the court—that is, leave of the court—to seek judicial review. It's probably the only area of law in Canada where you have to do that.
So a court won't even exercise its supervisory authority without first deciding whether it thinks the case is worth hearing. That's what this bill proposes with respect to citizenship revocation. First you have to ask a court if it will even hear the case, and then only if it gives permission to hear the case will there be a possibility for the court to set it aside using its supervisory authority.