In Canada, the term quasi-constitutional is used for laws which remain paramount even when subsequent statutes, which contradict them, are enacted by the same legislature. This is the reverse of the normal practice, under which newer laws trump any contradictory provisions in any older statute.

The normal practice, under which the more recent statute has the effect of nullifying any contradictory rules laid out in all earlier statutes, is known as "implied repeal." Implied repeal is the traditional way of ensuring that two contradictory laws are never in effect at the same time. The practice of implied repeal also reinforces the concept of parliamentary sovereignty or supremacy---that is, it reinforces the idea that the parliament or legislature cannot be restricted by any external limit, including past actions of the legislature itself.

A quasi-constitutional statute uses a "primacy clause" to achieve the apparently contradictory goals of respecting parliamentary sovereignty whilst retaining primacy in the face of later, contradictory statutes. A primacy clause is a provision stating that the statute can only be repealed or limited by a later statute if that later statute contains a primacy clause of its own, specifically stating that the new law is overriding the earlier, quasi-constitutional statute. For example, subsection 1(1) of the Alberta Human Rights Act reads "Unless it is expressly declared by an Act of the Legislature that it operates notwithstanding this Act, every law of Alberta is inoperative to the extent that it authorizes or requires the doing of anything prohibited by this Act." The human rights codes of some other provinces use similar language.

Canadian constitutional scholar Peter Hogg provides this summary:

In Canadian statutes, it is not uncommon to find "primacy clauses" that purport to declare that the statute containing the clause is supreme over other statutes, future as well as past. Such clauses are intended to defeat the doctrine of implied repeal, under which a later statute would impliedly repeal an inconsistent earlier statute to the extent of the inconsistency.

A quasi-constitutional law may be repealed or amended by means of an ordinary Act of the parliament or legislature, just like any other law. In this respect, therefore, such laws are not genuinely constitutional laws, which normally require some higher form of approval, such as the approval of multiple provincial legislatures, in order to be amended.

At the federal level, such laws include the Canadian Bill of Rights and the Official Languages Act. In Quebec, the Charter of the French Language and the Quebec Charter of Human Rights and Freedoms contain primacy clauses asserting quasi-constitutional status.

The primacy clause in the Canadian Bill of Rights asserts that no later provision of a later statute, which contradicts the Bill of Rights may prevail unless "it is expressly declared ... that it shall operate notwithstanding the Canadian Bill of Rights." The Quebec Charter of Human Rights and Freedoms states that contradictory acts do not apply "unless such Act expressly states that it applies despite the Charter."