Disallowance and reservation are historical constitutional powers that were instituted in several territories throughout the British Empire as a mechanism to delay or overrule legislation.
Originally created to preserve the Crown's authority over colonial governments, these powers are now generally considered politically obsolete, and in many cases have been formally abolished.
A bill assented to by a governor-general or colonial governor would pass into law, but might still be disallowed by the King- or Queen-in-Council, usually within a certain timeframe after its passage.
Sometimes a bill that had passed into law might be suspended by its own terms until the sovereign's pleasure was made known, i.e. until the British government had advised the colonial authorities whether they were prepared to accept the legislation.
The 1926 imperial conference approved a committee report that stated: [A]part from provisions embodied in constitutions or in specific statutes expressly providing for reservation, it is recognised that it is the right of the Government of each Dominion to advise the Crown in all matters relating to its own affairs.
Use of disallowance and reservation in the states declined and eventually ceased, and both powers were formally abolished by the Australia Act 1986.
At the 1930 Imperial Conference, it was agreed that the United Kingdom would not reserve or disallow legislation without the approval of the Canadian cabinet.
Prime Minister John A. Macdonald and his Conservative successors regularly advised disallowance for provincial legislation, generally citing respect for private contracts, preservation of federal jurisdiction, and the rights of local minorities as justification.
[9] The election of the Liberals under Wilfrid Laurier in 1896, who regarded both reservation and disallowance as unwarranted interference in provincial affairs, began to see the use of the powers subside.
The last disallowance of a provincial law occurred in April 1943, in relation to Alberta legislation restricting land sales regarding Hutterites and "enemy aliens.
[13] Comparative public law scholar Richard Albert has argued that both powers have fallen into "constitutional desuetude," which occurs "when an entrenched constitutional provision loses its binding force upon political actors as a result of its conscious sustained nonuse and public repudiation by preceding and present political actors.
Trudeau, a constitutional scholar, demurred, believing that disallowance would ultimately cause more political harm, and that it was better to have the conflicting matters adjudicated.