‘Concurrency’ refers to the allocation of responsibility for a subject matter of legislation to both the federal and provincial levels of government. Concurrent allocation of responsibility arises from the fact that the powers assigned to the federal Parliament and provincial legislatures by sections 92-95 of the Constitution Act, 1867 are expressed in quite general terms. As a result, the constitutional powers of the federal Parliament and the provincial legislatures overlap. Within the area of overlap, either Parliament or the legislatures have constitutional power to legislate. The power to legislate within this area of overlap is thus said to be concurrent.

Some commentators have called for expansion of the use of concurrency in the Constitution. They reason that by so doing provinces will have greater flexibility to develop legislative programs tailored to their special needs and desires. This proposal has drawn a reaction. Extensive use of concurrency, say the opponents, allows certain provinces to exercise more power than others, a situation fundamentally at odds with the notion of equality inherent in Canadian citizenship. The proponents counter that extensive use of concurrency merely affects the level at which citizens take decision – federal or provincial. It does not affect the governmental power available to citizens.