Mr Paul Gogarty (Green Party, Dublin Mid West) accused the Government of scaremongering.
"They are the ones sowing the seeds of disengagement. They are accusing Irish voters of being at worst selfish, or at best, misled or even stupid.
"Yet, they have been rightly accused by the pro-Nice treaty Opposition parties of not properly arguing Ireland's corner at the Nice summit."
He said that the biggest red herring of the entire campaign was that a rejection of the Nice treaty would somehow prevent enlargement.
"The Green Party supports enlargement and would not be fighting this flawed treaty if enlargement was prevented.
"The Nice treaty's so-called protocol on enlargement has little to do with EU enlargement and a lot more to do with shifting the balance of power between the 15 member states."
Speaking on Tuesday night, the party leader, Mr Trevor Sargent, said the referendum provided people with the last chance to vote on the future of the European Union as equal citizens of that entity.
"If the Nice treaty goes through eight countries will be in a position to steamroll ahead with enhanced co-operation. In order to maintain our equality, we urge a No vote.
"It is our last chance to vote to retain Ireland's entitlement to a Commissioner."
He warned that it was the State's last chance to retain a veto in over 30 areas.
"If the Nice treaty goes ahead, Ireland will have seven votes out of 345 in a European Union of 27 states at the Council of Ministers."
Mr Brian O'Shea (Labour, Waterford) said there was no doubt that enlargement will happen if Ireland rejected the treaty for a second time.
"The European Union will find another way. If this is the case, however, how will the applicant countries look at us and how will the other member-states react? There would be a loss of goodwill towards Ireland that would take a long time to get over."
Mr O'Shea recalled that during the summer of 1972 he had spent weeks campaigning for a No vote in the referendum on EU entry.
"A great fear on the Left at the time was the danger to the future of our traditional industries. I was on the losing side, but, unfortunately, those fears were realised in significant part.
"In spite of that, however, I have long been convinced that membership of the European Union has contributed to social and economic development that would have been impossible had Ireland remained in isolation. I do not accept that voting for the ratification of the Nice Treaty is damaging to the national interest."
The Sinn Fein chief whip and Europe spokesman, Mr Aengus Ó Snodaigh, described the debate as "mockery of democracy," adding that only 113 minutes out of a total of 22.5 hours debate were allowed for those opposing the treaty.
