The Democratic Left leader, Mr Proinsias De Rossa, has moved to dampen speculation of a merger between his party and Labour. As he joined other political figures in paying tribute to Mr Spring, he made it clear that he saw Labour and Democratic Left remaining separate entities.
"I look forward to working with the new Labour leader in a spirit of co-operation that will enable each party to advance and to bring their distinct political philosophies and historical backgrounds to work for the development of progressive politics in Ireland," Mr De Rossa said. "This can best be done by each party respecting the integrity and independence of the other." He said Mr Spring had been a pivotal figure in Irish political life for more than 15 years.
"He packed a remarkable level of achievement into that period as a Dail deputy, party leader, government Minister and European statesman. His contribution to political life at home and on the broader international stage has been immeasurable."
He said Mr Spring had earned his place in history not just for leading his party to unprecedented success but also for the major part he played in Anglo-Irish relations and in the achievement of the ceasefires.
The Taoiseach, Mr Ahern, said Mr Spring had given outstanding service to the Irish people.
"He presided over the modernisation of the Labour Party and turned it into a major political force in the State," he said. "He provided a unique continuity through the major Anglo-Irish initiatives of the past 15 years, from the Anglo-Irish Agreement to the Framework Document."
???ail was "correct and courageous" and crucial to getting peace. He had also made a major contribution in international affairs. It was important "that his contribution should be publicly acknowledged by all of us who worked with him as a colleague."
The Fine Gael leader, Mr John Bruton, said he was sorry Mr Spring was resigning. "He was a very talented party leader and Minister - patriotic, cool in a crisis and loyal to his colleagues. His leadership of the Labour Party identified it with the modernisation of Ireland in the 1990s."
He said Mr Spring was respected widely throughout the world as Minister for Foreign Affairs. "Time and again foreign leaders spoke privately and publicly to me about the way Dick Spring has helped international relations while serving Ireland's interests exceptionally well."
The Progressive Democrats leader and Tanaiste, Ms Mary Harney, said that while she did not always see eye to eye with Mr Spring, she had great regard for him as a fine parliamentarian. "He has made an outstanding contribution to Irish political life, and his work in relation to the peace process in Northern Ireland particularly represented true and tremendous service to the State."
The president of Sinn Fein, Mr Gerry Adams, paid tribute to Mr Spring's efforts in the peace process, saying that "he consistently worked to remove obstacles to inclusive talks without preconditions". Mr Albert Reynolds, Taoiseach when Mr Spring was Tanaiste, was reticent about Mr Spring's departure. "I don't have any reactions to anything these times. I've finished having reactions."
Dr Garret FitzGerald, the former Fine Gael leader and former Taoiseach, said he was not surprised at Mr Spring's decision. He felt the period he and Mr Spring spent in government had been very fruitful. "We did very well to get through four and three-quarter years and get as much done as we did."
Dr FitzGerald added: "He was a very good foreign minister. I did think that for him to take on Foreign Minister, Northern Ireland, Tanaiste and leader of the Labour Party was a bit much, considering his health."
The SDLP leader, Mr John Hume, paid a warm tribute to Mr Spring and thanked him for "his tireless commitment to resolving the situation in the North". He said he played a crucial role in the shaping of the modern European Union, particularly during his period as Tanaiste and Minister for Foreign Affairs.
"I know from my own experience of the respect with which he is held in Europe. He is a great listener and a first-class leader. Although he is now closing a chapter of his life, I hope he will continue to employ his considerable talents in the interests of the people of Ireland and of Europe." Mr Reg Empey of the Ulster Unionist Party said that while Mr Spring had made "positive noises" about amending the Constitution, he had never produced anything.
The Alliance Party leader, Lord Alderdice, said Mr Spring was a man of great ability and energy and he had the greatest of respect for him. "I believe history will judge him not only one of the most influential but also one of the most positive influences in Irish politics in his generation."