Introduction
On May 30, 2025, the Supreme Court of Canada (the Court) in Opsis Airport Services Inc. v. Québec (Attorney General)1 unanimously held, in a consolidated appeal of two cases, that Québec's Private Security Act (PSA) is constitutionally inapplicable to the appellant companies' activities at federally regulated airports and at marine facilities, respectively, pursuant to the doctrine of interjurisdictional immunity (IJI).
The decision is a significant reaffirmation of the continued relevance of IJI to protect federal powers and undertakings (such as airports, marine ports, banks, and interprovincial transportation projects such as cross-border pipelines) from the application of certain provincial laws. In particular, the decision reaffirms that the final say over the manner in which activities falling within the core of federal power operate remains within the exclusive jurisdiction of the federal government.
Given the federal government's current focus on advancing projects of national interest, the decision is a timely reaffirmation of a doctrine that has been used successfully by proponents of federal undertakings to advance their projects in an orderly and efficient manner notwithstanding provincial and/or municipal opposition. Conversely, and of equal importance to proponents of intraprovincial undertakings, the Court also reaffirmed that IJI reciprocally protects the core of exclusive provincial powers, and that such projects may conversely be interjurisdictionally immune from the application of federal laws that impair core provincial powers.
Background
The appellants Opsis Airport Services Inc. (Opsis) and Québec Maritime Services Inc. (QMS) were each charged with contravening the PSA. Opsis provides airport security services, operating an emergency call centre at the Pierre Elliott Trudeau International Airport (Trudeau Airport) in Montréal. QMS operates in the marine transportation sector, providing loading services at the international shipping terminal in La Malbaie.2 The activities of Opsis and QMS are regulated by federal legislation.
The PSA provides for a licensing scheme for private security activities and establishes a self-regulated board (the Bureau) charged with enforcing the statute and making regulations, issuing licences and directives to licensees, and providing mandated training to licensees. The Bureau possesses broad powers, including the power to suspend, cancel or refuse renewal of licences, which may be invoked...
