AG Canada v. AG Ontario (Labour Conventions Case)
Rule established
The power to implement treaties in domestic law follows the division of legislative powers in the constitution. In a federal state, the central government cannot legislate on matters within provincial/state competence merely because it has entered a treaty on that subject.
Facts
- Canada ratified ILO Conventions on hours of work, weekly rest, and minimum wages
- Federal Parliament enacted implementing legislation
- Ontario argued labour regulation fell within provincial legislative competence under the BNA Act
Issue
- Whether the federal government can legislate on provincial subjects to implement international treaties.
Held
- Treaty-making is an executive (federal) power
- But legislative implementation must follow the constitutional distribution of powers
- Labour is a provincial subject; federal Parliament cannot legislate on it merely because a treaty exists
- Federal legislation struck down
Ratio Decidendi
In a federal state, the distribution of legislative powers between the centre and the units cannot be altered by the executive's treaty-making power. Implementation of treaties on matters within state/provincial competence requires state/provincial legislation.
How to use it in an exam
- Authority for dualist approach in federal states
- Shows treaty-making ≠ treaty-implementation power
- Relevant for PIL Unit 1 (IL and municipal law relationship)
- Key line: "In AG Canada v. AG Ontario (1937), the Privy Council held that the federal government cannot legislate on provincial subjects merely because it has entered a treaty on that subject."
Source
Source: [1937] AC 326
This is an educational summary, not the judgment itself. Cite the reported version in professional or academic work.