The Taoiseach has rejected claims that he is "hiding behind lawyers" about the controversy surrounding the £25,000 cheque which he co-signed on behalf of Fianna Fail and which ended up in the personal finances of the former taoiseach, Mr Charles Haughey.

He had been challenged in the Dail repeatedly by the Opposition about clarifying his comments to the House on September 10th, 1997, when the Fianna Fail leader's allowance was raised.

The Labour Party leader, Mr Ruairi Quinn, called on Mr Ahern to explain why he did not disclose the circumstances about the cheque to the Dail in 1997 or that he was a co-signatory.

The Fine Gael leader, Mr John Bruton, also called for him to publish correspondence between him and the Moriarty tribunal which debarred him from making a statement to the Dail to correct the record.

The Taoiseach said that when the issue was raised on September 10th, 1997, by the former Labour leader, Mr Dick Spring, it related to 1982 to 1987 when Fianna Fail was in opposition. Mr Ahern explained then that he did not believe anything was wrong. "The record of that date stands to this day and is not erroneous."

He said he had received advice from the Attorney General that he could release the correspondence which related "exclusively to my obligation of confidentiality to the tribunal and which does not disclose the identity of third parties or in any way impinge on their constitutional rights".

Mr Bruton had accused the Taoiseach of "hiding behind lawyers", a comment which Mr Ahern said he could not let go. The Taoiseach then read out a short prepared statement and extracts of letters from the Moriarty tribunal, one of which he had received on Monday.

Mr Ahern again insisted that he had acted properly and brought the matter to the attention of the Moriarty tribunal so that any significance could be determined by the inquiry. He said that in most recent contacts with the tribunal they had "again forcefully reiterated the necessity for confidentiality during this phase [outside public sittings] of their work".

One of the two extracts from tribunal letters stated that "the statement furnished by An Taoiseach clearly affects the interests of other persons. It would be irresponsible of the tribunal to encourage any person dealing with it to think that circumstances you describe would justify the disclosure of such information in public otherwise than in the course of the tribunal's sittings."

It also stated that "the tribunal would expect that persons in a position of responsibility would not deviate from these principles".

Mr Ahern said that after he received this letter lawyers for the party wrote back to the tribunal and received a reply on Monday. The letter referred to Opposition demands for a statement from the Taoiseach on the leader's allowance, and a request from the party solicitors to write to the Ceann Comhairle to apprise him of the instructions and directions from the tribunal to the Taoiseach.

The tribunal's letter stated that the request "effectively amounts to an invitation to the tribunal to become embroiled in a political controversy. This could result in the tribunal becoming identified with one side or other of a political controversy and is something which might lead to the compromising of the independence of the tribunal."

Writing to the Ceann Comhairle could be seen to be "an attempt to influence the Ceann Comhairle in the way in which he exercises his powers or exercises any discretion in the discharge of the duties of his office".

The letter went on to say that the tribunal could not presume to direct the Taoiseach "or indeed any responsible office-holder as to how they should act in relation to this matter." The tribunal acknowledged the "care with which your clients [the Taoiseach] appear to have observed the principles governing the operation of the tribunal's workings".

Mr Ahern said in conclusion: "That is my position. That explains the matter and I have no more to say." Mr Bruton said that the Taoiseach's obligation to the House superseded his obligation to the Moriarty tribunal.

He said it was unsatisfactory that the Taoiseach was unable or unwilling to answer questions to the House about actions he took and documents he signed. Mr Ahern replied that he was "unable, not unwilling".