[2] In 1999, this statute was the subject of a watershed ruling in M. v. H. by the Supreme Court of Canada that established the equality of spousal rights for same-sex couples under Canadian law.
According to the Preamble, the purpose of the law is "to encourage and strengthen the role of the family; ... to recognize the equal position of spouses as individuals within marriage and to recognize marriage as a form of partnership; ... to provide in law for the orderly and equitable settlement of the affairs of the spouses upon the breakdown of the partnership, and to provide for other mutual obligations in family relationships, including the equitable sharing by parents of responsibility for their children".
Such exclusion perpetuates the disadvantages suffered by individuals in same‑sex relationships and contributes to the erasure of their existence.According to one of the attorneys in the M. v. H. case, the ruling dealt "a body blow to discrimination" in Canada.
[3] Although the ruling applied specifically only to the Ontario law, the constitutional principles declared by the court had far-reaching implications for all other provinces in their treatment of same-sex couples' rights.
This ruling did not affect the legal definition of marriage, and applies only to cohabiting partners in a common-law relationship, who have significantly fewer rights than married spouses in some areas, especially relating to division of property upon separation.