Under the 1937 Constitution, power was given to the three great organs of State. Legislative power was given to the Oireachtas. It has neither explicit, implicit nor inherent powers to conduct the type of inquiry at issue but could initiate a tribunal of inquiry.
The issue of specific future legislation establishing a statutory inquiry or a committee of inquiry was not before the Supreme Court, she said. As the law stood, the houses of the Oireachtas had no inherent power to conduct this type of inquiry.
In contrast to the British Constitution, Ireland had laws that the Oireachtas could not change - the Constitution - and there was a marked distinction between laws which were constitutional and those which were not. The Dáil was not a court of the nation and there was no concept of it being the "Great Inquisitor" of the nation such as at Westminster.
Rejecting arguments that legislative power included power to establish a committee such as the Abbeylara subcommittee (ASC), she said it was noteworthy such a committee was neither explicitly nor implicitly written into the Constitution and that the system was not utilised by the legislature previously. There were also very significant rights under the Irish Constitution which were protected by the Constitution and the courts, including the right to fair procedures and the right to State protection and vindication of a person's good name.
In her opinion, indications by a parliamentary committee member of their views on the subject under inquiry while the committee was at hearing would be contrary to the concept of fairness.