Labour Party leader Eamon Gilmore accused Bertie Ahern of being a "lame-duck Taoiseach leading a government of deadbeats" in the Dáil today.
Mr Gilmore was speaking during Leaders' Questions in the Dáil this afternoon.
He asked Mr Ahern what assurances he could give the public that his credibility had not been damaged or his authority diminished by the continuing controversy surrounding his personal finances.
Mr Ahern replied emphatically that his credibility was intact and denied that his authority had been diminished.
He added that he thought it "unfair" that he had to face a tribunal in the Dáil as well as the Tribunal "on the outside".
Asked what proportion of his time was being taken up with appearances at the Mahon tribunal and the defence of his position, Mr Ahern said he had spent "'six or seven minutes discussing his personal finances at a press conference yesterday".
'The rest of the time I have been working on preparing tomorrow's Budget," he said.
He also denied suggestions that he gave implicit approval to the National Lottery to enter talks with Manchester businessman Norman Turner about becoming involved in his plans for a casino in Dublin.
"I acted totally properly in relation to a plan for a casino in Dublin. I didn't do anything improper," he said.