The Minister for Community, Rural and Gaeltacht Affairs, Mr Ó Cuív, has called on the electorate to vote Yes in the Nice referendum.
Although he voted No in the previous referendum, he said yesterday that a number of issues that were of concern to him then have now been addressed by the EU and the Government.
Speaking at the Patrick MacGill Summer School in Glenties, Co Donegal, Mr O Cuiv, stressed that this referendum is different.
"In technical terms what the referendum seeks to do is insert words into the Irish Constitution that will have the effect of validating what is in the Nice Treaty but also with the proviso that we will not be part of some common defence policy without another referendum."
He also dismissed the suggestion that Irish support for EU enlargement implies support for a European superstate or for an ambitious federalist project, and felt that "the more small countries that join the European Union, the more likely it is that a union in a fashion desired by the Government will be achieved".
He added that he was "absolutely stunned" at the stance being adopted by some of the anti-Nice campaigners. In the run-up to the first Nice referendum it was commonly agreed that enlargement was a good thing, and nobody was proposing withdrawing from the EU.
He said he was more than surprised now to hear some people playing the card that EU enlargement will lead to problems with illegal immigrants from Eastern Europe.
"It is now time to send a powerful signal to these countries that the Irish people want them to share with us and join in the union," he said.
The theme at yesterday's summer school was "Yes or No to Nice".
At a round table discussion last night Ms Maria Cronin, IBEC's director of strategy and EU affairs, said rejecting Nice had changed the perception of Ireland in other EU countries, and especially in the applicant countries.
She said that they were "mystified" how a country like Ireland, which had gained so much - and which was consistently positive in Eurobarometer polls - could vote No to the treaty.
She said there were two real possibilities if the Irish people reject Nice again.
The first was that "in the uncharted constitutional waters that will follow, the EU may degenerate into inactivity, inefficiency, and ultimately disintegration".
The second, more likely scenario, was that Ireland may become completely marginalised.
"Like it or not, the enlargement process is irreversible," she said.
She highlighted the fact that when the proposed enlargement was completed the EU market would rise from 370 million to nearly 500 million consumers, making it the largest developed market in the world, and double the size of our nearest competitor, the US.
"Turning our backs on those trying to enter the EU, those who consider us 'a role model', will ultimately alienate our potential allies and trading partners," she said.