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The Supreme Court Rules on the Provinces' Power to Regulate Cannabis

In Murray-Hall v. Quebec (Attorney General), 2023 SCC 10, the Supreme Court of Canada ruled that provinces have the power to prohibit personal cultivation of cannabis. In doing so, the Supreme Court also shed light on the scope of the constitutional power over health, commerce and criminal law, as well as the doctrine of federal paramountcy.


In 2018, Parliament passed the Cannabis Act, SC 2018, c. 16 (the "federal law"). Under this law, it is prohibited for an individual to possess or cultivate more than four cannabis plants in their home.

A few days before the adoption of the federal law, the National Assembly of Quebec adopted the Cannabis Regulation Act, CQLR, c C-5.3 (the "provincial law"), which completely prohibits the possession and cultivation of cannabis plants at home, regardless of the number of plants (the "challenged provisions").

The appellant filed an application before the Superior Court of Quebec seeking a declaration that the provisions were ultra vires and of no force or effect.

Decisions of the Superior Court and the Court of Appeal

After analyzing the legislative history of drug criminalization and legislative debates, the Superior Court concluded that the pith and substance of the challenged provisions was "to completely prohibit the personal cultivation of cannabis because it harms the health and security of the public", which fell under the federal criminal law power. The Superior Court found that the rest of the provincial law was valid under ss. 92(13) and 92(16) of the Constitution Act, 1867, but that the challenged provisions could not be saved by the ancillary powers doctrine because the encroachment of these provisions on the federal jurisdiction in criminal matters is serious. The Superior Court suggested that it would have been possible for the province to restrict the number of plants rather than banning them altogether. Finally, the Superior Court stated that provincial law was a form of "colourable legislation”, which appeared to fall under provincial jurisdiction, but whose pith and substance fell under the criminal law power. In light of its conclusion on validity, the Superior Court did not find it necessary to address the argument on operability.

The Court of Appeal of Quebec overturned the first instance decision, finding that the challenged provisions must be placed in the overall context of the provincial law and that the pith and substance of the challenged provisions is to "put in place one of the means chosen to ensure the effectiveness of the state monopoly granted to the Société québécoise du cannabis".

As for the argument on federal paramountcy, the Court of Appeal found that there was no frustration of purpose because the text of the federal law did not expressly confer any positive right to possess or cultivate cannabis plants for personal purposes, and that, in any event, the criminal law power could not provide a right, only prohibit. Finally, the Court of Appeal stated that both laws were "driven by the same desire to combat the harms associated with consumption”, making them "more complementary than conflicting laws”.

Supreme Court Decision

I. Validity

(a) Characterization

Writing for a unanimous court, Wagner C.J. concluded that the pith and substance of the challenged  provisions is "to ensure the effectiveness of the state monopoly in order to protect the health and security of the public, and of young persons in particular, from cannabis harm". According to the Supreme Court, by redirecting cannabis consumers to the state monopoly entrusted to the Société québécoise du cannabis, the prohibitions on personal cultivation ensure control over the quality of the products offered, awareness of the health risks associated with cannabis consumption, and compliance with minimum age purchase standards.

The Supreme Court emphasized that it is necessary to characterize the challenged provisions in light of their interaction with the regulatory regime to which they belong. In doing so, the Supreme Court’s approach differed from that of the Superior Court, which focused on the validity of the specific provisions, and, once it found them to be invalid, examined whether the provisions were sufficiently integrated into the otherwise valid law.

The Supreme Court added that a global approach is crucial to distinguish the purpose of the law from the means chosen to achieve it. Thus, while the Superior Court affirmed that "the prohibitions set out in ss. 5 and 10 are not means, but rather the very purpose of these provisions,” the Supreme Court concluded that the prohibition on personal cultivation is "part of the monopolistic logic intended by the Quebec legislature" and is therefore a means of achieving public health and safety objectives.

Unlike the Superior Court, the Supreme Court held that the fact that these objectives could have been achieved by restricting the number of plants rather than by a total prohibition is far from being determinative, as "considerations relating to the efficacy or wisdom of the means chosen are not helpful at the characterization stage”.

The Supreme Court rejected the assertion that the challenged provisions are a form of "colourable legislation" aimed at re-enacting the criminal law prohibitions repealed by Parliament. First, the Supreme Court confirmed that courts should be reluctant to find legislation to be "colourable”. Second, even though the Court acknowledged that "some uneasiness" has been expressed by Quebec parliamentarians regarding the dangers of cannabis, these remarks should rather be interpreted as reflecting "a general concern about the risks arising from cannabis consumption, particularly for younger individuals", which pertains to provincial jurisdiction. In any event, the Court emphasized that "it is the substance of the legislation that needs to be characterized, not speeches in Parliament or utterances in the press".

Finally, the Supreme Court concluded that the legal effects of the challenged provisions — criminal prohibitions and fines associated with them — as well as the practical effects — obliging cannabis consumers to obtain their supply from the state monopoly — confirm the pith and substance described above. Moreover, the Court noted that the fines, ranging from $250 to $750, are relatively modest, unlike those resulting from the application of criminal provisions under the former federal regime.

(b) Classification

The Supreme Court determined that the pith and substance of the challenged provisions falls under the jurisdiction of the provinces under s. 92(13), jurisdiction over property and civil rights, and s. 92(16), residual jurisdiction over purely local or private matters within the province, of the Constitution Act, 1867.

While it is true that prohibitions similar to those provided in the challenged provisions may have been previously adopted by Parliament, this is explained by the double aspect doctrine: such prohibitions may be valid under federal power over criminal law to suppress a social evil, but they also fall under provincial jurisdiction over health and commerce by steering consumers to a controlled source of supply.

The Court added that the fact that the prohibition on possessing plants is absolute does not make it a criminal prohibition. In fact, many provincial penal provisions are absolute prohibitions.

II. Operability

The Supreme Court held that, in the presence of a double aspect, the operability aspect must be dealt with as precisely as possible, "to avoid eroding the importance attached to provincial autonomy".

The Supreme Court affirmed that there is no conflict of application because it is possible to comply with both provincial and federal law by not engaging in self-cultivation. The Supreme Court also concluded that there is no frustration of purpose because the purpose of the federal law cannot create a positive right to self-cultivation given the "essentially prohibitory" nature of the criminal law power. In addition, the Court held, a simple reading of the federal provisions demonstrates that they do not purport to confer such a right.


The Murray-Hall decision takes a broad view of the provinces’ power to regulate cannabis. More generally, the decision has significant implications for the federal division of powers. It confirms that provinces may prohibit decriminalized activities under the double aspect doctrine. It also reaffirms the presumption of constitutional validity and reminds us that courts will not lightly conclude that a provincial legislation is “colourable” or inoperative. This is particularly so when, as in this case, the Attorney General of Canada chooses not to intervene in the judicial debate.

The authors of this post acted on behalf of the Cannabis Council of Canada and the Association québécoise de l’industrie du cannabis before the Supreme Court of Canada.



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