The courts have used long titles and other elements of the statutory context to ascertain the purpose and legislative intent behind a provision. Early cases allowed consideration of the long title only where there was ambiguity. In Minister for Industry and Commerce v Hales , the High Court accepted that the long title formed part of the Act, but held that it was permissible to call in aid the long title in the interpretation of a provision of an Act only where the provision was unclear or ambiguous. The leading case is East Donegal Co-operative Marts Ltd v Attorney General in which the Court stressed the importance of the long title to the Act in forming a part of the context and background of the Act, in the light of which its provisions should be construed. Walsh J departed from the more restrictive rule in Hales , in allowing for a determination of ambiguity only after the long title had been considered. He stated:
"The long title and the general scope of the Act of 1967 constitute the background and the general scope of the context in which it must be examined. The whole or any part of the Act may be referred to and relied upon in seeking to construe any particular part of it, and the construction of any particular phrase requires that it is to be viewed in connection with the whole Act and not that it should be viewed detached from it. The words of the Act, and in particular the general words, cannot be read in isolation and their content is to be derived from their context. Therefore, words and phrases which at first sight might appear to be wide and general may be cut down in their construction when examined against the objects of the Act which are to be derived from a study of the Act as a whole including the long title. Until each part of the Act is examined in relation to the whole it would not be possible to say that any particular part of the Act was either clear or unambiguous."
"in my opinion, the plain language used in ss.30 and 36 is so clear and unequivocal that the long title may not be looked at, or used for the purpose of limiting or modifying that language."
McCarthy J, however, emphasised the usefulness and importance of the long title. He stressed that the long title was as much a part of an Act as any other provision and stated:
"it is not, in my opinion, a question of ambiguity in the construction of particular provisions; it is a question of giving a schematic interpretation where such is the plain intent of the statute ."