17 Judgment No. CCZ 2/18 Constitutional Application No. CCZ 86/15 The authorities show that retrospectivity as a method of implementing civil legislation is a proper tool of modern government, provided it is used with appropriate restraints. In British Columbia v Imperial Tobacco Canada Ltd [2005] 2 SCR 473 the Supreme Court of Canada held that: “The absence of a general requirement of legislative prospectivity exists despite the fact that retrospective and retroactive legislation can overturn settled expectations and is sometimes perceived as unjust: see E. Edinger, ‘Retrospectivity in Law’ (1995), 29 U.B.C.L. Rev. 5, at p. 13. Those who perceive it as such can perhaps take comfort in the rules of statutory interpretation in that they require the legislature to indicate clearly any desired retroactive or retrospective effect …”. In Gustavson Drilling (1964) Ltd v The Minister of National Revenue [1977] 1 SCR 271, cited by the respondents’ counsel, the same Court held at p 279 that: “The general rule is that statutes are not to be construed as having retrospective operation unless such a construction is expressly or by necessary implication required by the language of the Act. An amending enactment may provide that it is to be operative with respect to transactions occurring prior to its enactment. In those instances, the statute operates retrospectively.” P. W. Hogg in Constitutional Law of Canada 3 ed (1992) at p 1111 wrote: “Apart from s. 11(g), Canadian constitutional law contains no prohibition of retroactive (or ex post facto) laws. There is a presumption of statutory interpretation that a statute should not be given retroactive effect, but, if the retroactive effect is clearly expressed, then there is no room for interpretation and the statute is effective according to its terms. Retroactive statutes are in fact common. The power to enact retroactive laws, if exercised with appropriate restraints, is a proper tool of modern government. Section 11(g) diminishes this power only by excluding the creation of retroactive criminal offences. Other kinds of laws may still be made retroactive.” Section 11(g) of the Canadian Charter of Rights is in substance similar to s 70(1)(k) of the Constitution.