SC explain principles for amending an act retrospectively

The Apex Court in Hitendra Vishnu Thakur v. State of Maharashtra (1994) 4 SCC 602 held that a law which affects the substantive rights of any of the parties, the law cannot be retrospective. Every party has a vested right in substantative law but no such right exists in procedural law. From the law settled by this Court in various cases the illustrative though not exhaustive principles which emerge with regard to the ambit and scope of an Amending Act and its retrospective operation may be culled out as follows: (i) A statute which affects substantive rights is presumed to be prospective in o...