Presumption of constitutionality

It would be quite useful to refer to Irish Law Reform commission report about the presumption that every statute is constitutionally valid:"Where, in the case of a statute which post-dates the 1937 Constitution, two interpretations of a provision are open to a court, one which is in accordance with the Constitution and the other which would render the provision unconstitutional, the interpretation which would render the provision constitutional is presumed to have been intended by the Oireachtas. The presumption of constitutionality is a strong one, which is defeated only where the construction of a provision as constitutional would involve the effective substitution or amendment of the provision in question. It may result in a highly restrictive construction of a statutory provision, in order to save it from unconstitutionality. The rule was set out by the Supreme Court by Walsh J in East Donegal Co-op v Attorney General :

"An Act of the Oireachtas, or any provision thereof, will not be declared to be invalid where it is possible to construe it in accordance with the Constitution; and it is not only a question of preferring a constitutional construction to one which would be unconstitutional where they may both appear to be open but it also means that an interpretation favouring the validity of an Act should be given in cases of doubt." Although the presumption imports some consideration of legislative intent into the interpretation of a provision, it was stated, in East Donegal, to be limited by the literal approach to interpretation. Thus where the clear and unambiguous words of a provision have an effect which is unconstitutional, the provision "cannot be given an opposite meaning." Any strained interpretation which amounted to a substitution of a constitutional provision for an unconstitutional one would, it was held, infringe the separation of powers.

It is safe to presume that Parliament enacts valid legislation and that there is no conflict between the statute and the constitution.In case of conflict it is the constitution that prevails.The presumption holds good even if the court finds that a part of the statute is not as per constitution.The following judgement of Canadian Court is worth stating"

As a result, it would be safe to assume that the legislature would have passed the constitutionally sound parts of the statute without the unsound parts. See Attorney‑General for Alberta v. Attorney‑General for Canada, [1947] A.C. 503, at p. 518; Schachter, supra, at p. 697.