An explanatory document, What the Treaty of Nice Means, was presented to the media in Dublin yesterday by the Institute of European Affairs.
The document, an outline of the main topics and implications of the Nice Treaty for the Republic, covers reform of EU institutions, enlargement, increased co-operation and developments in common foreign and security policies.
Presenting the document, the institute's director-general, Mr Joe Brosnan, said the Republic was facing another EU referendum against a background of low voter turnout and of declining support for the Yes option.
It was vital, he said, that the electorate took the trouble to inform themselves and to turn out and vote on the day.
Mr Brosnan said he believed the treaty would be carried by a narrower margin than indicated in current opinion polls.
If it was not carried, it was very hard to see how to proceed. It was possible that the Government could attempt to put another referendum before the people.
However, this would involve addressing and understanding the reasons for rejection before a second referendum could be called.
The reality was that Ireland's EU partners had no enthusiasm for "reopening the Nice Treaty", and final rejection by the Republic, the only state to hold a referendum on the treaty, would most likely see other states getting involved in arrangements among themselves.
This would lead to a situation where the Republic would be forced to reassess its relationship with the Union, and he did not believe the Irish people wanted this.
The briefing document is a summary of an in-depth study on the implications of EU expansion, prepared for the institute at the time of the negotiations which led to the Nice Treaty at the end of 2000.