Sinn Féin said today the decision to hold a second referendum on the Nice Treaty was "constitutionally suspect" and "undemocratic".
Party president Mr Gerry Adams said: "When the people said No, the Government should have gone to the other EU member states and renegotiated to take account of Irish concerns, but instead we have forced into a re-run".
Speaking in Dublin, Mr Adams questioned whether a referendum would have been run again in Germany or France without the inclusion of a protocol or a complete renegotiation of the treaty.
He said the treaty was not about Ireland's membership of the EU or specifically about enlargement as both would proceed regardless. Mr Adams said it was about the future governance of the EU and the treaty in its present form would change the rules in favour of big states.
He said: "It will create a two-tier, two-speed EU that favours bigger states, the loss of permanent representation on the EU Commission in an enlarged EU and the abolition of the veto in 30 policy areas.
"All of these will seriously undermine the strength of our voice in the EU," he said.
Sinn Féin TD for Dublin South West Mr Séan Crowe said: "We are satisfied with the way our campaign is going and with the response on the doorsteps".
