Fundamental constitutional principles and values of New Zealand law
This is a single section from Chapter 4. Read the full chapter here.
The presumption against retrospectivity
Legislation should not affect existing rights and should not criminalise or punish conduct that was not punishable at the time it was committed.
This presumption is part of the rule of law. The general rule is that legislation should have prospective, not retrospective, effect (Chapter 12 provides guidance on legislation that has a retrospective effect).