The former Taoiseach, Mr Albert Reynolds, said yesterday that it was time for Ireland to "repay some of the generosity" it enjoyed from the EU by voting Yes in tomorrow's Nice Treaty referendum.
Speaking at a final press conference in Dublin of the Irish Alliance for Europe, Mr Reynolds said membership of the union had paid off the past and would pay off even more in the future.
He was joined by a fellow former Taoiseach, Dr Garret FitzGerald, in warning of possible resentment from accession states if Ireland voted No.
Dr FitzGerald said the international goodwill built up by Ireland over the past 30 years "will be destroyed and disappear overnight" in such an outcome.
Blaming the last referendum defeat on a lack of campaigning and "defective politics", he said Ireland's best interests required a Yes vote.
Mr Reynolds said on the last occasion the government believed the result had been a foregone conclusion and "the Irish people were taken for granted."
Dr Patrick Hillery, the former president who signed Ireland's accession treaty to the EU in 1972, said he remained worried about the outcome, and urged "those who believe in Europe" to turn out and vote Yes.
Each enlargement of the union, he said, made Europe "a safer and a better place to live".
Former minister and PD TD Mr Des O'Malley said he would be ashamed if Ireland prevented others from benefiting from EU membership. The best guarantee that accession states remained part of free Europe was for them to become members of the EU, he said.
He remarked he was "unhappy" with the Government's attachment of a commitment to neutrality to the treaty, saying Ireland should not shirk its responsibility to protect the EU. However, he said, for the "greater good" he was advocating a Yes vote.
Dr FitzGerald also said it was undesirable for such a commitment to be in the Constitution. However, he said it was "a price worth paying" for the good of the country and of Europe.
Ms Angela Kearns, of Disability Alliance for Europe, stressed the benefits of EU enlargement in the protection of vulnerable citizens. Voting Yes, she said, would be "one of the greatest humanitarian acts Ireland will ever make as a nation".
