The chairman of the No to Nice Campaign, Mr Justin Barrett, has warned Irish neutrality would be jeopardised if the referendum was passed. "Our neutrality has been progressively diluted over the years in a number of ways," he added.
"There are our observer status in the Western European Union and our membership of Partnership for Peace, an issue on which the Taoiseach, Mr Ahern, failed to hold a promised referendum. However, we have never been directly involved in a military force for aggressive purposes before. That is what the Rapid Reaction Force is for, and Nice will bring it directly under EU control."
Speaking at a public meeting in Dublin, Mr Barrett said there were 30 areas where the Republic had a veto that would be handed over if the referendum was carried.
"One of them relates to the setting out of the rules under which structural and cohesion funding is granted. By voting No we retain our veto in this important area."
He accused the Minister of State for European Affairs, Mr Dick Roche, of failing to address the issues relating to the Nice Treaty.
"He talks about our membership of the EU and the benefits we have received over the past 30 years. . . The treaty would fundamentally alter our relationship with the EU and put those benefits in grave danger."
Mr Anthony Coughlan of the National Platform said a No vote would force the Government into having an honest debate on the economic costs and benefits of enlargement. "We will also retain the veto each EU member has at present, which is our safeguard against a two-class, two-tier EU.
"This veto can prevent the big states, led by Germany and France, establishing an inner EU state, with its own constitution, army, and harmonised taxes for the euro zone, and using the EU Commission, council, court and parliament to call the shots for the rest of us."
Mr Coughlan said Ireland was proud to be the only democratic state with a vote on the treaty. "We must not allow ourselves to be bullied."
Meanwhile, in a statement yesterday, the spokesman for Ireland for Europe, Mr Padraic Lyons, appealed to the No to Nice Campaign to remove the "race card" as an issue. He claimed some campaigners were attempting to stir up public fears by claiming enlargement would be followed by "a flood" of migrant workers.
Mr Lyons said a Yes vote would enable Europe to expand and develop to the benefit of Ireland and the rest of Europe.