Fianna Fail leader Micheal Martin has blamed wider society for a "lazy" consensus over how the country was run during recent years.
Insisting Brian Cowen and Bertie Ahern were not culpable either, he defended his right to call for radical political reform as he prepared to leave government after 14 years.
Mr Martin denounced as "ridiculous" the way Dail business is carried out and said the current system of appointing TDs to the Cabinet was not in the interest of the country.
But he suggested he was not in a position to make any changes to how the Oireachtas worked while a senior Cabinet member for more than decade.
"As a new party political leader I'm fully entitled to bring forward radical political reform proposals," he said.
"As a leader you are in a different position than as a member of a frontbench or a Cabinet."
But Mr Martin said he would not point the finger at ex-leaders Taoiseach Brian Cowen and his predecessor Bertie Ahern for not making much needed changes to the political system.
The Fianna Fail leader said there was a wider consensus in society that the economy was going well and nobody challenged how things were being done. "The consensus in relation to the political system became lazy," he said.
On his own right to change his mind on key issues, Mr Martin added: "One is always evolving one's thinking, learning and reflecting on whether or not your political system is fit for purpose."
Fianna Fail has called for what it brands a fundamental transformation of the Oireachtas with proposals that government ministers no longer serve as TDs during their time in Cabinet.