A new law ought to impose form on what is to follow, not on the past.

Law is called a rule prescribed ; which word prescribed has, in the sense in which it is here used, two significations : one, that the law is intended to provide for something thereby directed to be done, or not to be done ; and the other, that such law should be written or printed, or otherwise publicly notified previously to its intended operation, in order that those persons who are thereby called upon or bound to obey may be properly informed of their duties and responsibilities, and so that they may, as it is their duty to be, thoroughly acquainted therewith. Were the laws otherwise promulgated, it would be unjust to say, “ Ignorantia juris non excusat.” Laws, therefore, which are not so made are made in contravention of this maxim, and are called ex post facto, or, retrospective laws.

The Roman law was, however, more strict than English in this respect, for it did not in any case admit of a law being retrospective in its operation unless so expressly stated.

The meaning of the maxim is, that laws ought not to be retrospective in their operation, nor to apply to past transactions ; but should be made to take effect from the time of their being enacted, and apply to future transactions only ; and this is the construction which is always put upon the statutes of the present day, in the absence of any manifest intention to the contrary expressed upon the face of the statute.

According to Francis Bennion¹⁾ “The essential idea of a legal system is that current law should govern current activities.”

A simple application of this rule of law is, that an action or other legal proceeding commenced before the passing of an Act, in respect of a right of action accrued before the commencement of the Act, proceeds as before, notwithstanding that by the Act subsequently passed the right of action in similar cases be taken away, or that the proceedings in respect thereof be changed. Some cases would seem to show an exception to this rule ; but there is in, strictness no exception, the statutes under which those apparently excepted cases were decided, strictly considered, bearing the retrospective construction put upon them in the particular cases.

In an English case where the question to be considered was as to whether or not section 14 of the 19 and 20 Vict. c. 97 ; which enacts that the payment of principal or interest by one of several joint-contractors, etc, shall not prevent the operation of the Statute of Limitations ; was retrospective, the above maxim was considered and adopted by the court as one of obvious convenience and justice, and always to be adhered to in the construction of statutes ; and the statute referred to in the matter then under consideration was held not to be retrospective, there not being either any express clause or any manifest intention upon the face of it that it should so be. For, though the statute had not contained any express retrospective clause, yet, had it contained such manifest retrospective intention, that intention would have prevailed under the ordinary rule for the construction of statutes.

It has been stated in another case that the exception to the general rule that a statute is not to have a retrospective operation, especially so as to affect a vested right, must depend upon the words of the statute or the special nature of each case. And, again, the rule that statutes ought not to be construed retrospectively, unless an intention in the Legislature that they should be so construed distinctly appears, has been held not to apply to statutes which only affect the procedure or practice of the courts.

In India the legislative power to make law with retrospective effect is well recognised. Every sovereign legislature possesses the right to make retrospective legislation. The power to make laws includes power to give it retrospective effect. However Article 20(1) constitutes an exception to this general rule.

Retrospective: A statute is deemed to be retrospective which takes away or impairs any vested right acquired under existing laws, or creates a new obligation, or imposes a new duty, or attaches a new disability in respect to transactions or considerations already past²⁾.

In State of Gujarat and Anr. v. Raman Lal Keshav Lal Soni and Ors. ³⁾ it was held by the Constitution Bench that the legislature is undoubtedly competent to legislate with retrospective effect to take away or impair any vested right acquired under existing laws. What was, however, required was that since the laws are made under written Constitution, and have to conform to the dos and don'ts of the Constitution, neither prospective nor retrospective laws can be made so as to contravene fundamental rights.

In para 17 of Commissioner Of Income-Tax vs Mico Products Pvt. Ltd⁴⁾ Hon'ble Bombay High Court held that There is no doubt that the Legislature has the power to make a law retrospective. This includes a power to give retrospective effect to a taxing statute.

The general principle, however, seems to be that alterations in procedure are retrospective, unless there be some good reason against it⁵⁾. A person accused of the commission of an offence has no vested right to be tried by a particular Court or a particular procedure except insofar as there is any constitutional objection by way of discrimination or the violation of any other fundamental right is involved⁶⁾. It is well recognized that “no person has a vested right in any course of procedure”⁷⁾.

In The King v. Chandra Dharma⁸⁾, Lord Alverstone, C.J. observed as follows:

The Rule is clearly established that apart from any special circumstances appearing on the face of the statute in question, statutes which make alterations in procedure are retrospective.

In that case, Channell, J. also observed thus:

I wish to say that in my view a statute dealing only with procedure applies to past events as well as to future events, and to hold this is not to make the statute retrospective. The object of the statute, is only to affect the procedure, and it matters not whether the events in respect of which the proceedings are taken happened before or after the passing of the Act.

Article 20 is one of the pillars of fundamental rights guaranteed by the Constitution of India. It mainly deals with protection of certain rights in case of conviction for offences. When an individual as well as corporations are accused of crimes, the provisions of Article 20 safeguard their rights. The striking feature of the Article 20 is that it can’t be suspended during an emergency period.

This Article has set certain limitations on the legislative powers of the Union and State legislatures. The clause (1) of Article 20 protects individuals against ex post facto legislation, which means no individual can be convicted for actions that were committed before the enactment of the law. In other words, when a legislature declares an act to be an offence or provides a penalty for an offence, it can’t make the law retroactive so as to prejudicially affect the individuals who have committed such acts prior to the enactment of that law.

So no substantive criminal law in India can have retrospective application so as to prejudicially affect the individual.

Interpretation of Statutes (2018 (3) SCC 253) Taxing / Fiscal Statutes

It is a settled principle of statutory construction that every Statute is prima facie prospective unless it is expressly or by necessary implications made to have retrospective operations – Legal Maxim “nova constitutio futuris formam imponere debet non praeteritis”, i.e. 'a new law ought to regulate what is to follow, not the past', contain a principle of presumption of prospectively of a Statute

Para 28: Of the various rules guiding how legislation has to be interpreted, one established rule is that unless a contrary intention appears, a legislation is presumed not to be intended to have a retrospective operation. The idea behind the rule is that a current law should govern current activities. Law passed today cannot apply to the events of the past. If we do something today, we do it keeping in view the law of today and in force and not tomorrow's backward adjustment of it. Our belief in the nature of the law is founded on the bedrock that every human being is entitled to arrange his affairs by relying on the existing law and should not find that his plans have been retrospectively upset. This principle of law is known as lex prospicit non respicit : law looks forward not backward. As was observed in Phillips v. Eyre, a retrospective legislation is contrary to the general principle that legislation by which the conduct of mankind is to be regulated when introduced for the first time to deal with future acts ought not to change the character of past transactions carried on upon the faith of the then existing law.

In the case of Vallabhaneni Lakshmana Swamy and others vs. Valluru Basavaiah and others, the principle of Nova Consititutio Futuris Formmam Imponere Debt, Non-Praeteritis was applied and it was held by the Hon’ble Andhra Pradesh High court that it is a cardinal principle of construction that every statute is prima facie prospective, unless expressly or by necessary implication has been made to operate with retrospective effect. The general rule is to impose new burdens to the impair existing obligations.

In this case⁹⁾ our Hon'ble Supreme Court held that It is a cardinal principle of construction that every statute is prima facie prospective unless it is expressly or by necessary implication made to have retrospective operation¹⁰⁾. But the rule in general is applicable where the object of the statute is to affect vested rights or to impose new burdens or to impair existing obligations. Unless there are words in the statute sufficient to show the intention of the Legislature to affect existing rights, it is deemed to be prospective only 'nova constitutio futuris formam imponere debet non praeteritis'. In the words of Lord Blansburg, “provisions which touch a right in existence at the passing of the statute are not to be applied retrospectively in the absence of express enactment or necessary intendment”¹¹⁾.