Of Prime Minister Justin Trudeau’s campaign promises, legalizing marijuana is unlikely to be an urgent priority. True, in the lead-up to last month’s election, Mr. Trudeau stated that a Liberal government would move to legalize and regulate marijuana “right away”. And, on March 15, 2015, he told a Vancouver radio station that his government would bring forward legalization legislation in the first session of the 42nd Parliament.

Mr. Trudeau’s “mandate letters” (i.e., marching orders) to the Ministers of Justice, Health, and Public Safety each refer to “the legalization and regulation of marijuana”. He specifically instructs the Minister of Justice to “create a federal-provincial-territorial process”.

In Canadian politics, nothing says “make haste” quite like “create a federal-provincial-territorial process”.

Politics won’t work in pot’s favour. Members of Parliament will quickly find themselves preoccupied with other priorities, since most of their constituents won’t see legalized marijuana – as opposed to, say, improved roads and highways – as a tonic for their daily woes. (Some will, but those people shouldn’t be driving.)

The trickier hurdle may be legal. Unlike many of the Liberals’ campaign commitments, the legalization and regulation of marijuana likely can’t be achieved without provincial acquiescence. Though the federal government has the power to decriminalize pot, the regulation of recreational cannabis will fall, at least in part, within provincial jurisdiction.

For now, Mr. Trudeau has assigned the task of figuring out when and how to legalize and regulate marijuana to three members of his Cabinet. Here’s what their legal advisors might be telling them.


Parliament has exclusive jurisdiction over criminal law and procedure: Constitution Act, 1867, s. 91(27). To be upheld as valid under the federal criminal law power, legislation must entail a prohibition backed by a penalty with a valid criminal law purpose: see Reference re Firearms Act (Can.), 2000 SCC 31, [2000] 1 S.C.R. 783 (Firearms Reference”), at para. 27; Reference re Validity of s. 5 (a) Dairy Industry Act, [1949] S.C.R. 1, at pp. 49-50, per Rand J., aff’d (1950), [1951] A.C. 179 (P.C.) (“Margarine Reference”).

The federal government unquestionably has the power to legalize marijuana.

The Supreme Court of Canada has held that the federal prohibition of marijuana constitutes a valid exercise of Parliament’s criminal law power: Canada (Attorney General) v. PHS Community Services Society, 2011 SCC 44, [2011] 3 S.C.R. 134, at para. 52; R. v. Malmo-Levine; R. v. Caine, 2003 SCC 74, [2003] 3 S.C.R. 571, at para. 78. Cannabis is listed in Schedule II to the Controlled Drugs and Substances Act, S.C. 1996, c. 19 (“CDSA”), which makes it an offence to possess, traffic, trade, or produce pot: ss. 4-7.

“I need cite no authority for the proposition that Parliament may determine what is not criminal as well as what is”: Morgentaler v. The Queen, [1976] 1 S.C.R. 616, at p. 627, per Laskin C.J. (dissenting, but not on this point); see also R. v. Hydro-Québec, [1997] 3 S.C.R. 213, at para. 151; RJR—MacDonald Inc. v. Canada (Attorney General), [1995] 3 S.C.R. 199, at paras. 53-56, per La Forest J. “The criminal law is not frozen in time,” wrote Major J. in RJR—MacDonald. “Parliament can decriminalize what once was thought criminal”: at para. 204. Parliament could constitutionally legalize (or decriminalize) marijuana by amending the CDSA accordingly.


“If … Parliament removes marihuana entirely from the criminal law framework, Parliament’s continuing legislative authority to deal with marihuana use on a purely regulatory basis might well be questioned”: Malmo-Levine, at para. 72; see also PHS Community Services Society v. Canada (Attorney General), 2010 BCCA 15, 314 D.L.R. (4th) 209, at para. 137, aff’d 2011 SCC 44, [2011] 3 S.C.R. 134.

There will be no dispute that the Constitution gives Ottawa the power to legalize marijuana. To what extent it also empowers Parliament to regulate marijuana is less certain.

The issue is one of jurisdiction. Though the criminal law power belongs to Parliament, jurisdiction over “Property and Civil Rights in the Province” is provincial: Constitution Act, 1867, s. 92(13). The two heads of power are effectively complementary; federal laws that are struck down for being beyond Parliament’s criminal law jurisdiction are usually found to be within the provinces’ jurisdiction over property and civil rights: see Ian B. Lee, The Assisted Human Reproduction Act Reference and the Federal Criminal Law Power (2011), 90 Can. Bar Rev. 471, at p. 483. Where limitations on the sale and consumption of “a social drug such as tobacco or alcohol” (RJR—MacDonald, at para. 34) are concerned, the frontiers of federal authority are not entirely clear.

In RJR—MacDonald, tobacco companies challenged the constitutionality of the Tobacco Products Control Act, a federal law that largely banned the advertising or promotion of cigarette products and that prohibited the sale of tobacco products without standard health warnings. One of the arguments before the Supreme Court was that the legislation exceeded Parliament’s jurisdiction because it was beyond the scope of the criminal law power.

A majority of the Supreme Court disagreed. (The court split 7-2 on the federalism issue, though it also voted 5-4 to strike down the impugned statutory provisions as unjustified infringements of the right to freedom of expression under s. 2(b) of the Charter of Rights and Freedoms.)

“Parliament may validly employ the criminal law power to prohibit or control the manufacture, sale and distribution of products that present a danger to public health,” wrote La Forest J. in RJR—MacDonald. “Parliament may also validly impose labelling and packaging requirements on dangerous products with a view to protecting public health”: at para. 39. The federal tobacco regulations at issue in RJR—MacDonald were within Parliament’s jurisdiction because, La Forest J. said, “this legislation is directed at a public health evil and … it contains prohibitions accompanied by penal sanctions”: at para. 33.

The criminal law power will likely permit Parliament to regulate legal marijuana in order to protect public health.

There will, however, be constitutional limits on federal regulation. In Labatt Breweries of Canada Ltd. v. Attorney General of Canada, [1980] 1 S.C.R. 914, the issue was whether “Labatt’s Special Lite” beer, which contained 4% alcohol, violated s. 6 of the Food and Drugs Act, under which the federal government had promulgated regulations that defined “light beer” as containing no more than 2.5% alcohol. Labatt argued that the impugned provisions were unconstitutional because, among other reasons, they fell outside the limits of the criminal law.

The Supreme Court agreed. “[T]he right in the Federal Parliament and the Federal Government to establish the standards of production and content of this product … does not come within the criminal law reach as traditionally described in the authorities,” wrote Estey J., for the majority, at pp. 933-34. “I can find no basis, therefore, for this detailed regulation of the brewing industry in the production and sale of its product as a proper exercise of the federal authority in criminal law.”

Yet, Estey J. also indicated that, where health is concerned, Ottawa has a freer hand: “Where health is an aspect of criminal law … the answer is clear but here not helpful”: at p. 934; see also R. v. Wetmore, [1983] 2 S.C.R. 284, at pp. 288-89. In RJR—MacDonald, La Forest J. determined that this nexus between the legislative purpose of protecting public health and the exercise of Parliament’s criminal law was constitutionally significant; as he stated, at para. 32:

Given the “amorphous” nature of health as a constitutional matter, and the resulting fact that Parliament and the provincial legislatures may both validly legislate in this area, it is important to emphasize once again the plenary nature of the criminal law power. In the Margarine Reference, … Rand J. made it clear that the protection of “health” is one of the “ordinary ends” served by the criminal law, and that the criminal law power may validly be used to safeguard the public from any “injurious or undesirable effect”.

There has, however, been some dispute over just how “plenary” the criminal law power truly is, particularly where “health” is concerned. In Reference re Assisted Human Reproduction Act, 2010 SCC 61, [2010] 3 S.C.R. 457, the issue before the Supreme Court was whether certain provisions of the federal Assisted Human Reproduction Act – governing in vitro fertilization, surrogacy, and other practices associated with assisted human reproduction – represented a constitutional exercise of Parliament’s criminal law power or an unconstitutional intrusion into provincial jurisdiction. The court splintered, with four judges voting to uphold the impugned provisions as valid criminal law and four judges voting to strike them down because, in their view, they lacked a valid criminal law purpose. In a solo opinion that decided the outcome of the case, Cromwell J. effectively split the difference, concluding that some of the provisions were constitutional and others were not.

In delineating federal jurisdiction in the Assisted Human Reproduction Act Reference, the two factions agreed that Parliament may use its criminal law power to protect against a public health “evil”, but parted company over what such an evil must entail: see Ubaka Ogbogu, The Assisted Human Reproduction Act Reference and the Thin Line Between Health and Crime (2013), 22 Const. Forum 93, at p. 95. In her reasons, at paras. 55-56, McLachlin C.J.C. said:

Where human conduct may cause injurious or undesirable effects on the health of members of society, Parliament may prohibit it as a public health evil.

No constitutional threshold level of harm, as such, constrains Parliament’s ability to target conduct causing these evils. It is not apparent that the criminal law may only regulate the severest risks to individual[s’] health and safety, and not also prohibit less severe harms that are of public concern…. This said, … conduct with little or no threat of harm is unlikely to qualify as a “public health evil”.

For LeBel and Deschamps JJ., the Chief Justice’s definition was too expansive; it went, they said, “further than any previous judicial interpretation” of the criminal law power: at para. 239. They would have imposed an additional criterion – that the evil to be prohibited must be “real or apprehended”, and “[t]he reasoned apprehension of harm … must be real and must relate to conduct or facts that can be identified and established”: at paras. 234-36. Since assisted human reproduction was not, in their view, “conduct that is reprehensible or represents a serious risk to morality, safety or public health”, “inherently harmful”, or “an evil needing to be suppressed”, Parliament could not use its criminal law power to regulate it: at para. 251 (emphasis added). The Chief Justice, for her part, criticized her colleagues’ approach to the criminal law as one that would “substitute[] a judicial view of what is good and what is bad for the wisdom of Parliament” and “enlarg[e] the judiciary’s role in assessing valid criminal law objectives”: at para. 76.

As Prof. Hogg notes, LeBel and Deschamps JJ.’s reasoning seems at odds with Supreme Court decisions that have upheld federal food and drug regulations under Parliament’s criminal law power, “since food and medicine are neither inherently harmful nor an evil in need of suppression”: Peter W. Hogg, Constitutional Law of Canada (Toronto: Carswell, 2013), at 18.2. Five years after the Assisted Human Reproduction Act Reference, those food and drug cases remain good law, and LeBel and Deschamps JJ.’s position has not commanded a majority of the court.

It follows that Parliament will be able to use its criminal law power to regulate the production, distribution, and consumption of cannabis in order to protect public health. For federal regulation to pass constitutional muster, however, it will have to be directed to the suppression of conduct that, at least, “may cause injurious or undesirable effects on the health of members of society” (per McLachlin C.J.C.) or, more strictly, “is reprehensible or represents a serious risk to morality, safety or public health” (per LeBel and Deschamps JJ.).

Ironically, then, the constitutionality of federal regulations on legal marijuana may turn on Ottawa’s ability to demonstrate that the uncontrolled distribution and consumption of cannabis – which it will just have legalized – is inherently dangerous. Mr. Trudeau is already speaking this language; he has, for instance, described the status quo as “making marijuana too easy to access for our kids, and at the same time funding street crime, organized gangs and gun runners”. If Parliament proceeds by removing cannabis from Schedule II of the CDSA, then any further steps it takes to regulate it will likely have to be for the purpose of combatting these hazards to public health and safety.

For those who want to liberalize access to marijuana as much possible, these constitutional limitations won’t be good news. And there’s more. Recall that, to be valid criminal law, a federal enactment must impose a prohibition backed by a penalty with a criminal law purpose: Firearms Reference at para. 27. It follows that “[t]he federal criminal law power may only be used to prohibit conduct”, not to encourage it: Assisted Human Reproduction Act Reference, at para. 38, per McLachlin C.J.C. To keep safely within its constitutional limits, the federal government will likely only be able to restrict the cultivation and distribution of legal marijuana, not to promote it.

Ottawa can legalize marijuana, but its power to regulate it will be limited. So will the provinces’.


As any Canadian who has ever tried to buy beer before a long weekend knows, “social drugs” are also regulated at the point of sale by provincial law: see, e.g., Liquor Control Act, R.S.O. 1990, c. L.18; RJR—MacDonald, at para. 38.

In 1883, the Privy Council in London (then Canada’s final court of appeal) confirmed that legislation governing the sale of alcohol was within the jurisdiction of the provincial legislatures: Hodge v. The Queen, [1883] UKPC 59, [1883-1884] 9 App. Cas. 117. The next year, the Supreme Court of Canada struck down as unconstitutional Parliament’s effort to establish its own licensing requirements for liquor sellers: McCarthy Act Reference, unreported; see R.C.B. Risk, Canadian Courts Under the Influence, 40 U.T.L.J. 687 (1990), at pp. 715-21. As Justice Fish of the Supreme Court of Canada noted in an extrajudicial commentary, “[t]ogether, Hodge and the McCarthy Act Reference made clear that that the provinces had exclusive jurisdiction to regulate the local sale of alcohol”:  Morris J. Fish, The Effect of Alcohol on the Canadian Constitution … Seriously, 57 McGill L.J. 189 (2011), at para. 61.

So far as alcohol is concerned, the provinces have not only the power to regulate, but also (with certain limitations) the power to prohibit. In Ontario (Attorney General) v. Canada (Attorney General), [1896] UKPC 20, [1897] A.C. 199 (“Local Prohibition Reference”), the Privy Council determined that:

A law which prohibits retail transactions, and restricts the consumption of liquor within the ambit of the province, and does not affect transactions in liquor between persons in the province and persons in other provinces or in foreign countries, concerns property in the province which would be the subject matter of the transactions, if they were not prohibited, and also the civil rights of persons in the province.

Recall that “Property and Civil Rights in the Province” is a provincial head of power under s. 92(13) of the Constitution Act, 1867. By the mid-twentieth century, the question litigated in Canada’s courts of appeal wasn’t actually whether the provinces had jurisdiction to prohibit alcohol, but rather whether Parliament did: see Ontario (Attorney General) v. Canada Temperance Federation, [1946] UKPC 2, [1946] A.C. 193; Fish, at paras. 71-73.

So what happens if, once marijuana is legalized, a province refuses to play ball?

Say the Government of Saskatchewan were to decide that, notwithstanding Parliament’s having amended the CDSA to remove the criminal prohibition of marijuana, and despite federal regulations governing its production and distribution, it would seek to obstruct access to legal cannabis. The province could pass legislation or promulgate regulations to restrict sales to persons over the age of 30: cf. The Alcohol and Gaming Regulation Act, 1997, S.S. 1997, c. A-18.011 (“AGRA”), s. 2 (defining “minor”). Or it could limit marijuana retail to a single, government-owned outlet, conveniently situated in Scott, Saskatchewan, population 75: cf. AGRA, ss. 12-14 (setting out the powers and responsibilities of the province’s Liquor and Gaming Authority). How might courts resolve the impasse that would ensue?

Assuming that the provincial regulations were able to survive a Charter challenge, they would be vulnerable to attack as an unconstitutional intrusion into the federal domain of criminal law. “[T]he provinces may not invade the criminal field by attempting to stiffen, supplement, or replace the criminal law … or to fill perceived defects or gaps therein”: R. v. Morgentaler, [1993] 3 S.C.R. 463. The 1993 Morgentaler case was a challenge to Nova Scotia legislation that sought to restrict access to abortion after the Supreme Court of Canada struck down comparable provisions in the Criminal Code in 1998: see R. v. Morgentaler, [1988] 1 S.C.R. 30. The court ruled that the province could not prevent what Parliament had permitted – in that case, by its legislative inaction.

Abortion is legal under federal law because Parliament declined to respond to the Supreme Court’s 1988 Morgentaler decision. Marijuana would be legal because Parliament had decided to legalize it. It is difficult to imagine that, in the face of more explicit federal permission, provincial legislation purporting to restrict access to legal cannabis would be any more likely to survive judicial scrutiny.

But what if Saskatchewan, in our example, presented its strict provincial regulations as consistent with the regulation of marijuana at the federal level? The province could then argue that, unlike the Nova Scotia legislation at issue in the 1993 Morgentaler case, its marijuana restrictions are merely to effectuate Ottawa’s legislative scheme, not to thwart or supplement it. Mr. Trudeau may himself lend some weight to this argument by vesting responsibility for the cannabis file in the Minister of Public Safety, as his mandate letters suggest he will. Since, as discussed above, the federal criminal law power will only permit federal regulations that restrict the production and distribution of cannabis, federal red tape may actually strengthen a recalcitrant province’s constitutional argument for imposing its own limitations on the sale of cannabis.

In that case, the constitutionality of Saskatchewan’s regulations will turn on the doctrine of federal paramountcy. The rule is that, in the case of conflict between federal and provincial law, the provincial law is inoperative to the extent of the inconsistency.

The Supreme Court has recognized two broad categories of cases in which federal laws will trump provincial ones. The first category comprises cases in which “there is an operational conflict because it is impossible to comply with both laws”: Alberta (Attorney General) v. Moloney, 2015 SCC 51, at para. 18; see also 407 ETR Concession Co. v. Canada (Superintendent of Bankruptcy, 2015 SCC 52, at para. 24. Such inconsistency occurs “where one enactment says ‘yes’ and the other says ‘no’ … [and] compliance with one is defiance of the other”: Multiple Access Ltd. v. McCutcheon, [1982] 2 S.C.R. 161, at p. 191, per Dickson J.

The second category includes situations in which, “although it is possible to comply with both laws, the operation of the provincial law frustrates the purpose of the federal enactment”: Moloney, at para. 18; see also Bank of Montreal v. Hall, [1990] 1 S.C.R. 121, at p. 154. “The focus of the inquiry”, wrote La Forest J. in Bank of Montreal, “must be on the broader question whether operation of the provincial Act is compatible with the federal legislative purpose”: at p. 155.

In Law Society of B.C. v. Mangat, 2001 SCC 67, [2001] 3 S.C.R. 113, the inconsistency was between federal law, which provided that non-lawyers could represent parties in proceedings before the (federal) Immigration and Refugee Board, and provincial law, which barred non-lawyers from doing so. The two laws were not expressly contradictory; one could comply with both simply by retaining a lawyer. Yet, the Supreme Court held that the provincial law was inoperative to the extent of the prohibition on non-lawyers; since “there is an enabling federal law, the provincial law cannot be contrary to Parliament’s purpose,” which was to “establish[] an informal, accessible (in financial, cultural, and linguistic terms), and expeditious process, peculiar to administrative tribunals”: at para. 72.

As Prof. Hogg has observed, the “frustration-of-federal-purpose test … requires the courts to interpret the federal law to determine what the federal purpose is, and then to determine whether the provincial law would have the effect of frustrating the federal purpose. If the answer is yes, then paramountcy renders the provincial law inoperative”: Peter W. Hogg, Paramountcy and Tobacco (2006), 34 S.C.L.R. (2d) 335, at p. 340.

In our hypothetical example, a court might well find Saskatchewan’s restrictions on the sale of legal marijuana to be inoperative under the frustration-of-federal-purpose test. The trouble, as Prof. Hogg notes, is that “there is no objective way of ascertaining the purpose of a particular federal law, and no objective way of determining whether a provincial law would frustrate that purpose”: Hogg, Paramountcy and Tobacco, at p. 342. Courts therefore have enormous discretion at each stage of the test.

If the purpose of the legalization and regulation of marijuana at the federal level is, in Mr. Trudeau’s words, to “mak[e] it more difficult for young people to access it”, then provincial efforts to restrict access to cannabis could well be said to further, rather than frustrate, that federal purpose. Under the doctrine of paramountcy, a conflict typically will not arise where the provincial law is more restrictive than the federal law that overlaps it: Moloney, at para. 26; Saskatchewan (Attorney General) v. Lemare Lake Logging Ltd., 2015 SCC 53, at para. 25. That could well be the case here, since, unlike the federal law at issue in Mangat – which “provide[d] for a positive entitlement” (Moloney, at para. 26) – federal regulations on cannabis would have to create restrictions, not entitlements, in order to constitute a valid exercise of Parliament’s criminal law power.

In Rothmans, Benson & Hedges Inc. v. Saskatchewan, 2005 SCC 13, [2005] 1 S.C.R. 188, the Supreme Court considered a case of overlapping enactments in which the impugned provincial restrictions were more onerous than the requirements of federal criminal law. At issue was an apparent conflict between s. 30 of the federal Tobacco Act, which allows shopkeepers to display tobacco products in their stores, and s. 6 of Saskatchewan’s Tobacco Control Act, which prohibits such displays in any place in which persons under the age of 18 are permitted. The issue was whether the doctrine of federal paramountcy rendered the Saskatchewan law inoperative.

Writing for a unanimous court, Major J. held that it did not. First, he concluded that there was no operational conflict, because “[a] retailer can easily comply with both s. 30 of the Tobacco Act and s. 6 of The Tobacco Control Act … by admitting no one under 18 years of age on to the premises or by not displaying tobacco or tobacco-related products”: at para. 22. The provincial law, he said, “simply prohibits what Parliament has opted not to prohibit in its own legislation and regulations”: at para. 23.

Nor did Saskatchewan’s legislation frustrate Parliament’s purpose. As Major J. stated, at para. 25:

Both the general purpose of the Tobacco Act (to address a national public health problem) and the specific purpose of s. 30 (to circumscribe the Tobacco Act’s general prohibition on promotion of tobacco products set out in s. 19) remain fulfilled. Indeed, s. 6 of The Tobacco Control Act appears to further at least two of the stated purposes of the Tobacco Act, namely, “to protect young persons and others from inducements to use tobacco products” (s. 4(b)) and “to protect the health of young persons by restricting access to tobacco products” (s. 4(c)).

Depending on how Parliament chooses to approach the legalization and regulation of marijuana, the reasoning of the Supreme Court’s decision in Rothman’s, Benson & Hedges could well be used to uphold prohibitory provincial regulations on the sale of cannabis, despite the doctrine of paramountcy. In any case, a party seeking to challenge such provincial laws on paramountcy grounds would bear a heavy burden. As Gascon J. stated for a majority of the Supreme Court in Moloney, at para. 27:

In keeping with co-operative federalism, the doctrine of paramountcy is applied with restraint. It is presumed that Parliament intends its laws to co-exist with provincial laws. Absent a genuine inconsistency, courts will favour an interpretation of the federal legislation that allows the concurrent operation of both laws….  Conflict must be defined narrowly, so that each level of government may act as freely as possible within its respective sphere of authority. [Citations omitted.]

Advantage: Saskatchewan.


Parliament unquestionably has the power to end the criminal prohibition of marijuana. That same power will permit it to regulate legal cannabis for the purpose of protecting public health and public safety, but only restrictively.

When it comes to retail distribution, however, federal regulation will run up against provincial jurisdiction. Though federal law will prevail over provincial law to the extent that the two are in conflict, a court may decline to find such inconsistencies where it is possible to comply with both laws at once and where the provincial law can be said not to frustrate Parliament’s purpose, however the court defines it.

Mr. Trudeau’s goal will be to ensure that our stubborn Saskatchewan hypothetical remains the stuff of law school exams, not court proceedings – hence the “federal-provincial-territorial process” that he has instructed the Minister of Justice to create. Still, the Liberal government may soon find that, though Ottawa can decide how that process begins, it has less control over where it ends.

The bottom line is this: How the provinces play their constitutional cards will determine how marijuana is legalized and regulated across Canada. In the haze of Canadian federalism, no one government can create a joint solution.


With thanks to my McCarthy Tétrault colleagues Awanish Sinha, Sabrina Lyon, and Justin Shoemaker, as well as to Prof. Adam Dodek and Benjamin Oliphant, for their helpful comments.

Adam Goldenberg
Adam Goldenberg is a lawyer at McCarthy Tétrault LLP. He is an adjunct professor at the Faculty of Law, University of Toronto. He was a law clerk to the Chief Justice of Canada and to the judges of the Ontario Court of Appeal, and he was chief speechwriter for the Leader of the Opposition in Parliament and a senior adviser in the Ontario government.  

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