In Canadian constitutional law, the doctrine of paramountcy establishes that where there is a conflict between valid provincial and federal laws, the federal law will prevail and the provincial law will be inoperative to the extent that it conflicts with the federal law. Unlike interjurisdictional immunity, which is concerned with the scope of the federal power, paramountcy deals with the way in which that power is exercised.
Paramountcy is relevant where there is conflicting federal and provincial legislation. As Major J explained in Rothmans:
|"||11. The doctrine of federal legislative paramountcy dictates that where there is an inconsistency between validly enacted but overlapping provincial and federal legislation, the provincial legislation is inoperative to the extent of the inconsistency....||"|
Claims in paramountcy may arise from two different forms of conflict:
First, ... there can be a domain in which provincial and Dominion legislation may overlap, in which case neither legislation will be ultra vires, if the field is clear; and, secondly, ... if the field is not clear, and in such a domain the two legislations meet, then the Dominion must prevail.
Historically, the doctrine was interpreted very strictly. When there was any overlap between federal or provincial laws the federal law would always render the provincial law inoperative even where there was no conflict. It was over time that courts and academics began to interpret the power as only applying where conformity to one law would necessarily violate the other. The Supreme Court of Canada adopted the latter interpretation in the decision of Smith v. The Queen. The Court held that there must be an "operational incompatibility" between the laws in order to invoke paramountcy.
The modern use of the paramountcy doctrine was articulated in Multiple Access v. McCutcheon. In that case, both the provincial and federal governments had enacted virtually identical insider trading legislation. The Court found that statutory duplication does not invoke paramountcy as the court had the discretion to prevent double penalties. Instead, paramountcy can only be invoked when the compliance with one means the breach of the other.
A later example of this doctrine was in the decision of Law Society of British Columbia v. Mangat, where the Court found an operational conflict between the provincial Law Society Act prohibiting non-lawyers from appearing in front of a judge and the federal Immigration Act which allowed non-lawyers to appear before the immigration tribunal.
The extent to which each branch of the paramountcy test can apply was explored in several cases decided by the SCC in November 2015, which have come to be known as the "paramountcy trilogy." The majority in each of these held that:
Côté J wrote vigorous dissents in all three cases, arguing that the majority's interpretation of the first branch conflicts with the clear standard of impossibility of dual compliance as a result of an express conflict expressed in prior jurisprudence, which was succinctly expressed in Multiple Access as "where one enactment says 'yes' and the other says 'no'; 'the same citizens are being told to do inconsistent things'; compliance with one is defiance of the other." As well, the majority's interpretation of the second branch conflicts with the Court's prior ruling in Mangat, in that "harmonious interpretation of both federal and provincial legislation cannot lead this Court to disregard obvious purposes that are pursued in federal legislation."