LEGAL PRINCIPLE: STATUTORY INTERPRETATION – Retrospective Legislation – Presumption Against Retrospectivity – Applicability to Vested Rights
PRINCIPLE STATEMENT
Prima facie, an Act deals with future and not with past events. If this were not so, the Act might annul rights already acquired, while the presumption is against the intention. It is a fundamental rule of English law that no statute shall be construed so as to have a retrospective operation unless its language is such as plainly to require such construction; and the same rule involves another and subordinate rule to the effect that a statute is not to be construed so as to have greater retrospective effect than its language renders necessary.
RATIO DECIDENDI (SOURCE)
Per Wali, JSC, in Adesanoye & Ors v. Adewole & Anor (2000) NLC-361998(SC) at pp. 24–25; Paras D–A.
"Prima facie, an Act deals with future and not with past events. If this were not so, the Act might annul rights already acquired, while the presumption is against the intention. It is a fundamental rule of English law that no statute shall be construed so as to have a retrospective operation unless its language is such as plainly to require such construction; and the same rule involves another and subordinate rule to the effect that a statute is not to be construed so as to have greater retrospective effect than its language renders necessary."
EXPLANATION / SCOPE
Statutes are presumed to operate prospectively unless clear language compels retrospective construction. This presumption protects vested rights from being disturbed by subsequent legislation. Retrospective application may annul acquired rights or impose new liabilities for past conduct, which is disfavored. Where retrospective intent is manifest, courts limit such effect to the minimum required by the statutory language. The principle lex prospicit non respicit (law looks forward, not backward) underpins this rule. Clear words are necessary to overcome the presumption; ambiguity is resolved against retrospectivity.