The Taoiseach, Mr Ahern, was among the many politicians to pay tribute to Mr Ruairí Quinn yesterday.
Mr Ahern said he had served Labour and the people of Ireland "with diligence, enthusiasm and distinction".
He has brought his vast experience and knowledge to bear in carrying out his ministerial roles since becoming minister of state at the Department of the Environment in 1982 to his role as minister for finance from 1994 to 1997.
"Ruairí Quinn and I are politicians of the same generation. We were elected in the same year. We both had the honour of being lord mayor of our capital city. We both served as minister for finance and we worked closely as cabinet colleagues."
The Fine Gael leader, Mr Enda Kenny, said Mr Quinn had led Labour with courage and conviction. "I am sure that even after his resignation, he will continue to play a significant role in Irish politics. His depth and breadth of experience will be of ongoing value both to the Labour party and to politics in general.
"Ruairí was a very effective minister for finance and minister for the environment, and I enjoyed working with him in government."
The Tánaiste and PD leader, Ms Harney, referred to Mr Quinn's commitment and energy.
"'I respect and admire his unquestioned ability. He is an exemplary parliamentarian and a dedicated politician, who has played a major role in Irish politics over 25 years." The chairman of the Green Party, Mr John Gormley, a constituency colleague in Dublin South East, said he regretted he never had the opportunity to serve in government with Mr Quinn. "He was a very competent minister for finance, and he served with distinction in all the offices he held while in government. He will be sadly missed by the Labour Party."
The former Fine Gael Taoiseach, Mr John Bruton, described Mr Quinn as one of the most successful ministers for finance in recent Irish history.
"He is a committed European, who won great respect, affection and influence for Ireland throughout Europe. He chaired the meetings that led to the agreement on the pact that allowed the euro to be launched.
"In his personal relations, he is exceptionally easy to deal with. He understands the needs of others and is always considerate."
The Lord Mayor of Dublin, Mr Dermot Lacey, praised Mr Quinn's leadership of the party and thanked him for the encouragement he had given him in his own political career.
"In 1993, I was honoured to succeed him on Dublin City Council upon his appointment as minister for enterprise and employment."
The Socialist Party TD Mr Joe Higgins, a former member of the Labour party, was critical of Mr Quinn.
He said that his retirement as leader was inevitable following the party's failure to make any gains in the general election.
"Mr Quinn was among those who led the Labour party away from any commitment to radical, socialist ideas. He was a leading supporter of the witch-hunt against the left in the late 1980s."
