LEGAL PRINCIPLE: STATUTORY INTERPRETATION – Retrospective Legislation – Distinction Between Procedural and Substantive Provisions
PRINCIPLE STATEMENT
If the new Act affects Mr. Vernazza's substantive rights, it will not be held to apply to proceedings which have already commenced, unless a clear intention to that effect is manifested. But if the new act affects matters of procedure only, then, prima facie, it applies to all actions, pending as well as future; for, as Lord Blackburn said: 'Alterations in form of procedure are always retrospective, unless there is some good reason or other why they should not be.'
RATIO DECIDENDI (SOURCE)
Per Uwaifo, JSC, in Adesanoye & Ors v. Adewole & Anor (2000) NLC-361998(SC) at p. 16; Paras D–F.
"If the new Act affects Mr. Vernazza's substantive rights, it will not be held to apply to proceedings which have already commenced, unless a clear intention to that effect is manifested. But if the new act affects matters of procedure only, then, prima facie, it applies to all actions, pending as well as future; for, as Lord Blackburn said: 'Alterations in form of procedure are always retrospective, unless there is some good reason or other why they should not be.'"
EXPLANATION / SCOPE
The presumption against retrospectivity applies differently to substantive and procedural provisions. Substantive provisions affecting vested rights require clear legislative intent for retrospective application. Procedural provisions, however, presumptively apply to pending actions—they regulate how courts operate, not what rights exist. This distinction reflects that procedural changes do not disturb accrued rights but merely alter the mechanism for enforcing them. However, even procedural changes may be excluded if they would create injustice or impair substantive entitlements. The classification determines the applicable presumption.