“Schachter v. Canada, 1992 CanLII 74 (SCC), [1992] 2 S.C.R. 679, 93 D.L.R. (4th) 1, remains the seminal authority regarding constitutional remedies. Lamer C.J.C. identified the court’s obligation to fashion a remedy for a constitutional breach and the scope of such remedies, at p. 695 S.C.R.:
Section 52 of the Constitution Act, 1982 mandates the striking down of any law that is inconsistent with the provisions of the Constitution, but only “to the extent of the inconsistency”. Depending upon the circumstances, a court may simply strike down, it may strike down and temporarily suspend the declaration of invalidity, or it may resort to the techniques of reading down or reading in.
Lamer C.J.C. set out three steps to be followed in determining the appropriate remedy for a Charter breach. First, the court is to define the extent of the impugned law’s inconsistency with the Charter. Second, it should select the remedy that best corrects the inconsistency. Third, the court should assess whether the remedy ought to be temporarily suspended.
Turning to the first step, we hold that the common law definition of marriage is inconsistent with the Charter to the extent that it excludes same-sex couples.
With respect to the second step, in our view the remedy that best corrects the inconsistency is to declare invalid the existing definition of marriage to the extent that it refers to “one man and one woman”, and to reformulate the definition of marriage as “the voluntary union for life of two persons to the exclusion of all others”. This remedy achieves the equality required by s. 15(1) of the Charter but ensures that the legal status of marriage is not left in a state of uncertainty.”
Halpern v. Canada (Attorney-General), 2003 CanLII 264037 (ON CA) at 145-148.