European Commission President Romano Prodi today said the EU should bring forward a planned treaty-changing conference if Irish voters reject the Nice Treaty a second time.
Irish electors stunned the European Union last month by voting against the Nice treaty in a referendum. Ireland is expected to hold a second referendum on the treaty next year.
EU leaders have agreed to hold their next intergovernmental conference (IGC) in 2004. An IGC is required to amend EU treaties and to introduce fundamental constitutional reforms.
"What happens if, in spite of our best efforts, Nice is not ratified?" Mr Prodi asked in a speech to the European Parliament in Strasbourg.
"It is my duty, as Commission president, to foresee what repercussions the Irish No might have on the enlargement process," Mr Prodi said.
He said an Irish Yes to Nice was the best guarantee of enlargement, but added: "If it should prove unavoidable, we would have to bring forward the date of the next IGC."
"This would enable us to fulfil our solemn commitments (to the candidate countries seeking EU membership)," Mr Prodi said.
His comments will upset some member states as they push the treaty through their parliaments. The official EU line is that Nice must be ratified and that it would be unwise to speculate about what may happen if it fails to clear all the hurdles.
At a marathon, acrimonious summit in Nice last December, the EU leaders agreed a raft of institutional reforms to enable the Union to work more smoothly once it admits the new members.
The 15 member states have until the end of 2002 to ratify the Nice Treaty. Only Ireland is required by its constitution to put the treaty to a popular vote.
The EU plans to be ready to admit the first new members from 2003 if they are ready, allowing them to take part in the 2004 European Parliament elections.
A second Irish rejection of the Nice Treaty would imperil this timetable. Even with an earlier IGC, enlargement would become more complicated and require more time to go ahead.