A ‘convention’ is an uncodified rule of a constitution considered binding on political actors but not enforceable by the courts. The constitution of a country is comprised of both written or codified rules enforced by courts, and ‘unwritten’ rules or principles necessary for constitutional government. While conventions are more binding upon political actors than mere usages, it is not true that they are less binding than constitutional law. There is no particular hierarchy of types of constitutional rules. In many cases, constitutional conventions are more important than written constitutional provisions. What separates a convention from constitutional law is that the former is not judicially enforceable. Courts may recognize the existence of a ‘convention’, and even help define its nature and scope, but they do not provide remedies for the breach of conventions.
While Canada’s Constitution is most often associated with its ‘written’ documents – chiefly, the Constitution Act, 1867 and the Constitution Act, 1982 – in fact, Canada’s full constitutional framework is unintelligible without reference to a prodigious set of constitutional conventions. Consider two examples. Nowhere in Canada’s constitutional documents is it written that the government of the day must resign when it loses the confidence of the legislative assembly. Yet this central tenet of responsible government is at the core of Canadian constitutionalism, and a political crisis would ensue were its principles ignored by political actors. Similarly, while in a strictly legal sense the Governor General may refuse his or her assent to a Bill duly passed by both houses of Parliament, a constitutional convention has developed whereby the withholding of assent would be unconstitutional (see reservation and disallowance).
Conventions arise when there are precedents for a particular principle or practice; when political actors consider themselves or ought to consider themselves bound to follow the principle or practice; and when there are good reasons for the existence of the principle or practice. While the core meaning of a ‘convention’ may be clear, questions of application frequently arise, and political actors may heatedly dispute what precedents apply and what reasons are legitimate. While political actors, for example, are agreed on the confidence convention, what sort of measure exactly constitutes a withdrawal of confidence may be controversial.
- A. Heard, Canadian Constitutional Conventions: The Marriage of Law and Politics (Toronto: Oxford University Press, 1991).
- R.M. Dawson, The Government of Canada, 5th ed. by N. Ward (Toronto: University of Toronto Press, 1970).
- B. Reesor, The Canadian Constitution in Historical Context (Scarborough: Prentice-Hall, 1992).
- Re Resolution to Amend the Constitution,  1 S.C.R. 753.