The Taoiseach, Bertie Ahern, is under growing pressure to reveal details of the payments he received from wealthy businessmen when he was Minister for Finance in 1993.
Mr Ahern has confirmed that the tribunal is investigating a number of payments he received at the time, apparently to pay legal bills associated with his separation from his wife.
However, he has denied media reports that the amount received was between €50,000 and €100,000.
Opposition politicians have already raised concerns about the matter and are expected to seek a statement from the Taoiseach when the Dail resumes on Wednesday.
They are expected to seek information on how much was received, the identity of the donors, whether tax was paid on the money, if it was in the form of gifts or loans and why it was not declared to the Standards in Public Office Commission.
Reports this morning say unnamed cabinet ministers and junior ministers also want Mr Ahern to clear up the situation, with some of his trusted advisors telling him that the longer he leaves it unexplained, the more damage the controversy will inflict.