721, was a reference question posed to the Supreme Court of Canada regarding provisions in the Manitoba Act, 1870 stipulating the provision of French language services in the province of Manitoba.

Four questions were asked: The Court found that the Constitution Act, 1867, and the Manitoba Act, 1870, did require both languages and that those laws that were not in both languages were of no force and effect.

However, they were deemed temporarily valid for a time until translations could be re-enacted in order to avoid a legal vacuum in Manitoba and to ensure the continuity of the rule of law.

This reference was the first time that the courts in Canada had used the remedy of a delayed declaration of invalidity.

Despite its exceptional origins, this remedy has grown to become a preferred one in Canadian public law.