The refusal of the Taoiseach to deal with Dail questions relating to a cheque which he apparently signed and which was connected with Mr Charles Haughey's finances demonstrates once more the impact of tribunals on parliamentary proceedings and democratic accountability.

In fairness, it would appear there is little else the Taoiseach can do but wait for the Moriarty tribunal to take its course.

It is clear from the text of the letter from the tribunal which the Taoiseach read out in the Dail that he would be acting contrary to the clear wishes of the tribunal, though not necessarily contrary to its orders, if he were to give a detailed explanation of the matter.

But what this episode brings to the surface is the unhealthy tension which can arise between fact-finding tribunals dealing with essentially political matters and the constitutional role of the Dail in maintaining political accountability.

Article 28 of the Constitution states categorically that "the Government shall be responsible to Dail Eireann". This represents a clear constitutional commitment to democratic accountability. By making the Government responsible to the Dail as opposed to the Oireachtas(which also includes the Seanad and the President), the Constitution recognises the special democratic mandate of Dail deputies on account of their direct, and generally recent, election by the people. The Dail is, of course, a legislative assembly, although it shares its law-making role with the Seanad and President.

But, by virtue of Article 28, it is also the ultimate site of democratic accountability.

It is this accountability function which gives meaning to the role of parliamentary opposition. In the cabinet system of government which we inherited from Westminster, the government will ordinarily have a sufficient majority to carry through its legislative programme, even in the face of persistent opposition from other parties.

What no government, no matter how numerically strong, can constitutionally avoid is the obligation to answer to the Dail for its stewardship of the resources and welfare of the State. The opposition's duty is to ask the questions. The government's duty is to answer them.

Tribunals of inquiry serve an important fact-finding function, particularly when those under investigation are not amenable to parliamentary questioning. But tribunals are a costly luxury when they result from a failure by Dail deputies and government ministers to answer parliamentary questions with full faith and candour.

It seems to have been precisely such a failure which led to the expenditure of millions of pounds of taxpayers' money on the beef tribunal, which produced few tangible results.

The biggest danger posed by tribunals, particularly at the rate at which they are now being established, is that they may bring about a relocation of political accountability from the Dail, where it constitutionally belongs, to a judicial forum, where the primary emphasis is on proof rather than truth.

Granted, the rules of evidence followed at tribunals are designed to elicit the truth, but they are but a poor substitute for a full and frank parliamentary statement.

However, it appears that it is only in an ideal world that one can expect such statements. Parliamentary answers nowadays are characterised by parsimony rather than comprehensiveness.

In the present case, there is probably little to be lost by waiting until the Moriarty tribunal has taken its course and considered the Taoiseach's evidence and submissions. If it took 10 years to discover the cheque which is the subject of the controversy, another few weeks will scarcely make much of a difference.

But what is at stake is an important constitutional principle. The Dail is unambiguously the most appropriate forum in which to investigate matters touching on political integrity and the management of public finances. We must be wary of any arrangements, well-motivated though they may be, which interfere with that principle.

From the correspondence which the Taoiseach yesterday read into the record of the Dail, it would seem there is one important justification on this occasion for the approach being adopted, namely that confidential matters relating to third parties may be at stake.

This is certainly a legitimate concern, but it should not be used to withhold any more information from the Dail than is strictly necessary to protect those interests. Otherwise, Article 28 of the Constitution could scarcely be said to be fully honoured.

A related development that is more worrying is the recent refusal of the Criminal Assets Bureau to supply certain documentation to the Flood tribunal. Here we have the spectre of a police agency, which is essentially what CAB is, defying a tribunal established by a resolution of both Houses of the Oireachtas and presided over by a judge of the High Court.

This is just one of the many troublesome questions associated with the entire crime-control structure, including the CAB, which was hastily introduced in the wake of the Veronica Guerin killing.

This is not the place in which to evaluate the necessity for such a structure or the manner in which it is operating. But its recent attitude towards the Flood tribunal should persuade us to pause and reflect on the powers allocated to bodies such as the CAB, and the extent to which these powers may be subtly but surely leading to an erosion of democratic accountability.

An even greater cause of concern is the uncritical enthusiasm with which the courts have supported the swingeing powers accorded to the CAB in the confiscation of assets, even in the absence of full legal representation for those whose assets are being seized.

These episodes should motivate the Dail to set aside some time in order to consider its own role vis-a-vis tribunals and related bodies. In recent years both Oireachtas and government have established numerous review bodies, commissions of inquiry, tribunals and advisory bodies to investigate or deal with a wide range of issues.

The one issue that has largely escaped scrutiny is the working of the Dail itself. To the outsider at least, it often seems that the present Standing Orders are not exactly conducive to the promotion of a vibrant system of democratic accountability.

Nowadays, obviously, any such review should include an examination of the relationship between tribunals of inquiry and parliamentary questioning.

Tom O'Malley lectures in law at NUI Galway