The first part of the Supreme Court judgment in the Haughey case dealing with the constitutionality of the Tribunals of Inquiry Acts highlights once again - like the Goodman case before it - a significant fault line running through two parallel constitutional provisions.

In essence, the dichotomy is this: Articles 34-37 of the Constitution reserve - save for what for our purposes are immaterial exceptions - the discharge of judicial functions to the courts. In truth, a tribunal of inquiry is very much like a court: it is invariably presided over by a High Court judge; it follows court-style procedures; it can make the same ancillary orders as the High Court (discovery of documents, costs etc); the parties are represented by solicitor and counsel; and it investigates matters which often replicate the types of issues coming before both the civil and criminal courts.

Moreover, if a tribunal moves to investigate matters which might amount to a serious violation of the law, is it not in effect finding a person guilty of a serious offence without the safeguards (proof beyond reasonable doubt, jury trial etc) which Article 38 of the Constitution with its twin guarantees of trial in due course of law and jury trial affords?

Yet the Supreme Court has now twice held that a tribunal of inquiry is not exercising the judicial power of the State within the meaning of Article 34.1 of the Constitution, so the issue of the guarantee of trial of criminal offences in due course of law does not even arise, since if the tribunal is not a "court" in the sense understood by the Constitution: it is not "trying" a person for a criminal offence.

Why and how has this somewhat surprising result come about? The immediate answer given in both the Goodman and Haughey cases is that the functions of a tribunal of inquiry are purely investigative. The tribunal acts, so to speak, as a pure instrumentality of the Oireachtas and reports back to it on the facts which it has so found.

The Supreme Court has twice stressed that a tribunal has itself no enforcement powers. It relies completely on the High Court to enforce any order made by a tribunal, a power underscored by the Tribunal of Inquiry (Amendment) Act 1997 which empowers the tribunal to apply to the High Court for an order directing any named person to co-operate with it.

To that extent a tribunal of inquiry fails to satisfy the essential tests which mark off the administration of justice (reserved to the courts) from the performance of quasi-judicial functions which is the every-day task of hosts of administrative tribunals.

The court might also have added that one perhaps unintentional by-product of the recent Cabinet confidentiality referendum was to provide a form of indirect constitutional authority for the establishment of a tribunal of inquiry.

It may be recalled that this constitutional amendment permitted the High Court to order disclosure of cabinet discussions "by virtue of an overriding public interest, pursuant to an application in that behalf by a tribunal appointed by the Government or a Minister of the Government on the authority of the Houses of the Oireachtas to inquire into a matter stated by them to be of public importance."

In other words, just as the specific enumeration of a variety of miscellaneous matters in the Constitution - random examples include "census, felony" and Iris Oifigiuil (the Government gazette) - thought to prevent their complete abolition by the Oireachtas, so it might be argued that the Constitution now for the first time refers to the possibility of the establishment of a tribunal of inquiry implicitly clothes it with some form of constitutional protection.

And yet it might be thought that the response of the Supreme Court in Goodman and Haughey is completely formalistic and overlooks the practical realities of the matter. The present edition of Kelly's The Irish Constitution (of which the writer was co-editor) reacted coolly to the reasoning in Goodman, saying that: "It is certainly true that one could scarcely raise a constitutional objection just because a tribunal . . . is required to consider allegations of criminal impropriety, but it is surely a different matter where the tribunal is empowered to bring in specific findings of criminal wrong-doing. In such circumstances, it is surely cold comfort to the citizen concerned to be told that no specific penalty has been or could be imposed if he has nonetheless been stigmatised by a public finding that he has engaged in (possibly very serious) criminal wrong-doing."

Indeed, the dangers inherent in this are well illustrated by a contemporary British example: the background to the on-going Stephen Lawrence inquiry is that a number of youths were acquitted - in admittedly controversial circumstances - of serious charges following an unlawful killing in the course of a racist attack.

Despite the acquittal, this inquiry now seeks to establish the identity of the killers. In reality, the youths in question are being re-tried on the same "charges"; save, of course, that they have the limited comfort that if the inquiry finds them "guilty" this cannot result in the imposition of a criminal penalty.

As one leading Australian High Court judge said in 1981 in the course of dissenting from the majority conclusion that the establishment of a tribunal of inquiry to investigate an alleged bribery scandal: "It is a fine point to answer that the finding is not binding and does not of itself make the person liable to punitive consequences.

It is by fine points such as this that human freedom is whittled away . . . if a government chooses not to prosecute, the fact that finding is not binding on any court is of little comfort to the person found guilty; there is no legal proceeding which he can institute to establish his innocence. If he is prosecuted, the investigations and findings may have caused ineradicable prejudice . . ."

The second part of the judgment is likely to prove one of the most significant interpretations of the constitutional right to fair procedures since - ironically enough - Mr Haughey's brother successfully challenged the procedures adopted by an Oireachtas Committee investigating the aftermath of the Arms Trial in 1970.

In holding that the tribunal could not make potentially far-reaching discovery against banks accounts held by Mr Haughey and his family, the court has notably reaffirmed in a specific factual context a well-established principle of fair procedures, namely: hear the other side.

This decision clearly has important ramifications for this and other tribunals regarding the procedures which they must now adopt and follow and it will clearly delay the work of the Moriarty tribunal.

And while this second part of the judgment represents a notable victory for Mr Haughey and his accomplished legal team, the basic message of the Supreme Court's judgment is that to all intents and purposes the Tribunals of Inquiry Acts are now all but immune from constitutional challenge and that tribunals will be part of the legal and political landscape for some time to come.

Gerard Hogan lectures in law at Trinity College Dublin