The Fine Gael leader has called on the Taoiseach to resign, accusing Bertie Ahern of demeaning the profession of politics.
Enda Kenny said Mr Ahern's coalition partners, the Greens and the Progressive Democrats,were too cowardly to walk away from him and it now fell to the finance minister, Brian Cowen, to confront him.
In response, Mr Cowen said he would not take lectures from a man who had been rejected by the electorate.
He also said that he was not surprised at the vitriolic nature of Mr Kenny's statement.
A Green Party spokesman said the tribunal should be allowed to continue with its inquiry and comments such as those from Mr Kenny risk prejeudicing the work of the tribunal.
Speaking on RTÉ Radio's Saturday View, the Minister for Justice, Brian Lenihan accused the Fine Gael party of editing down the evidence before the Tribunal.
He said he was content to allow the tribunal to complete its work. Asked about Mr Kenny's assertion that it was a constant distraction to the work of government, Minister Lenihan said the issue had never come up at a Cabinet meeting.
In response to the statement a spokesperson for the Progressive Democrats said the Mahon Tribunal must see all of the evidence before it can judge the veracity, relevance and significance of it.
Much of Mr Kenny's statement, which was made in Castlebar, Co Mayo this morning, focuses on Mr Cowen.
He asked how Mr Cowen could sit beside a Taoiseach who had not paid his taxes, who had misled the Dáil about his tax affairs and who had refused to correct the record.
The Fine Gael leader claimed that the Taoiseach was using Mr Cowen as an accomplice to deceive the Irish people.
And he said he believed that if Mr Cowen did not act, he would bear responsibility for Mr Ahern continuing in office despite the compelling case for his removal.
Mr Kenny also accused the Minister for the Environment, John Gormley and the Minister for Health, Mary Harney, of choosing to put their ministerial seats of office ahead of getting clear explanations and accountability from the Taoiseach.
