The circumstances leading to the publication of the tribunal amendment legislation are unprecedented, said the Minister for Justice, Mr O'Donoghue.

They could not possibly have been foreseen when earlier tribunal legislation was before the Dail, he said, during a debate on the Bill to amend the terms of reference of tribunals.

The Minister said he did not pretend "this legislation is ideal". He had made it clear on a number of occasions why he would have reservations about anybody going to a tribunal in order to amend its terms of reference, "but I have been at pains to explain that the Attorney General was most careful in the approach which he deemed it necessary to make".

And he believed "history will say that the Government's actions were prudent, considered, wise and legitimate".

Introducing the Tribunals of Inquiry (Evidence) (Amendment) (No 3) Bill, he said it would enable the ail and Seanad Oireachtas to change a tribunal's terms of reference, subject to the tribunal's consent.

Dismissing Opposition criticism of the legislation, Mr O'Donoghue said it was as if the Opposition had come into the House "with a machine-gun and a full magazine and seeing no target, fires anyway".

He denied a suggestion by Dr Pat Upton, Labour's justice spokesman, that the legislation would effectively repeal the No 1 Act of 1998 relating to tribunals. "This is patent nonsense. The legislation now before the House amends the previous legislation to take account of the exceptional circumstances which now present themselves."

Dr Upton repeated the allegation that the advice of senior officials was ignored, "but he ignores the fact that the advice of the Attorney General" was accepted, the Minister said.

He rejected "in the most emphatic manner possible, in the most trenchant way that I can" any suggestion that there had been a conscious attempt by the Government "to be minimalist in our approach" because it had brought forward legislation to deal with these matters whenever it was required.

He also rejected Dr Upton's claim that there was no need for further legislation. How much more minimalist could one have become than not to produce any legislation? he said.

It was the Attorney General's advice, confirmed by independent counsel, that the legislation was necessary to "expressly provide for amendment of terms of reference of a tribunal".

This Government wished to have the fullest possible inquiry into the matters in question, he said. "It wants to ensure that there can be no successful challenge to the tribunal's work."

The overriding concern in the legislation "is to achieve a balance in what is brought forward, to ensure fair procedures and to uphold the principle of justice".

The integrity of the judicial process had to be preserved and "the onerous task placed on a tribunal needs to be uppermost in our minds in debating those same issues which arise in relation to this Bill".

Mr O'Donoghue said he explained in great detail precisely the terms under which the Attorney General presented himself to the chairperson of each tribunal.

A very important feature of the legislation was that the tribunal will be consulted before the making of the amendment and its consent to the amendment would be required, he said.