The former Labour Party leader and tánaiste Michael O'Leary has died after reportedly drowning in a swimming pool while on holiday in France.
Mr O'Leary retired as a District Court Judge on Monday, which was his 70th birthday. He will be buried in France.
The Taoiseach Bertie Ahern said he had learnt of the death of his former constituency colleague in Dublin Central with great sadness.
"During his time in the Dail from 1965 to 1987 he was a distinguished politician who was very much part of the process of liberalisation in Irish society," Mr Ahern said.
"Michael O'Leary was not just a politician. He was a man of many parts. As the political tide ebbed away from him in the 1980's he embarked on a new career in the law, qualifying as a barrister. In 1997 he became a Judge of the District Court.
"In private he was one of the wittiest and most entertaining men one could meet and he enjoyed a considerable gift as a mimic." Labour Party leader Pat Rabbitte said it was "with deep regret" he had learned of Mr O'Leary's death.
"Michael O'Leary had a distinguished career in different areas of public life over four decades. From student leader, to trade union official, to politician and eventually to the judiciary, he had a constant commitment to the principle of public service," Mr Rabbitte said.
"Michael was a formidable politician who was elected party leader at a very difficult time for the Labour Party. Despite subsequent difference and his departure from the Labour Party he retained the respect and affection of party colleagues."
Mr Rabbitte said the former party leader would be remembered in particular for "his pioneering work as Minister for Labour in the 1973-77 Fine Gael/Labour government".
Mr O'Leary was a native of Cork and educated at Presentation College before going on to University College Cork and Columbia University, New York.
He became a full-time official with the old Irish Transport and General Workers Union (ITGWU) and elected to the Dail in 1965 for the Labour Party. He served as an MEP from 1979 before being elected party leader in 1981.
He resigned the following year after the coalition collapsed and shortly afterwards joined Fine Gael. He was elected to the Dáil for the party in the old Dublin South West constituency in the November '82 election but lost his seat in 1992.
He later passed the bar exam and practised in his native Cork.
Fine Gael leader Enda Kenny expressed his sympathies and shock at hearing of Mr O'Leary's death. "I have fond memories of working alongside Michael in the [Fine Gael] parliamentary party following his decision to join Fine Gael in 1982," Mr Kenny said.
The Minister for Justice Michael McDowell today described Mr O'Leary as his good friend who will be greatly missed by many.
He also paid tribute to his political skills saying he "combined patriotism and good humour"
"Ireland owes a great debt of gratitude to Michael O'Leary for his courageous and innovative career in public life, as a trade unionist, public representative, a Minister and Tánaiste, and most recently as a judge."
Mr O'Leary is survived by his wife Mary.