The member states and the commission will pursue the enlargement negotiations with undiminished vigour and determination

Romano Prodi and Goran Persson

The results from two consituencies are still awaited.

"People have made the decision and we must respect that," said Ireland's Deputy Prime Minister, Mary Harney.

European Union leaders, however, have vowed to push ahead with plans to admit 12 new mostly East European states into the union.

"The member states and the commission will pursue the enlargement negotiations with undiminished vigour and determination, in line with our firm commitment given to the applicant countries," Swedish Prime Minister Goran Persson and European Commission President Romano Prodi said in a joint statement.

The 'No' vote is an embarrassment to the Irish Government

But there is little doubt that the Irish vote could delay its implementation.

The BBC's Angus Roxburgh says applicant countries will be dismayed, knowing that their efforts to join the European Union will all be in vain unless this unexpected problem is resolved

Turnout for the referendum was one of the lowest in Irish history: 32.9% of 2.9 million registered voters. Of these, 46% voted yes, and 54% voted no.

Neutrality

Prime Minister Bertie Ahern expressed dismay at the level of apathy. Before the results were in, he was quoted by newspapers as saying he was "hopeful, but not confident" of victory.

Ireland's main political parties and the powerful Roman Catholic Church urged a Yes vote, saying the treaty would secure peace and stability in Europe.

Only an estimated 30% cast their ballots

But the treaty's opponents, including the Greens, the republican Sinn Fein, socialists and a number of religious groups, say Ireland will lose generous EU subsidies if new, poorer members are admitted.

They also argue that ratifying the treaty would force Ireland to participate in the EU's 60,000-member Rapid Reaction Force, thus infringing on the country's traditional neutrality.

No 'finesse'

Among other things, the Nice Treaty alters the EU's decision-making procedures, reducing the scope of national vetoes, and increasing the range of questions decided by qualified majority voting.

It also re-allocates voting strengths in the European Parliament and Council of Ministers.

Before the vote, EU officials were quoted as saying that a vote against the treaty could not be "finessed".

On Friday, they said that certain parts of the treaty would have to be renegotiated in response to an Irish rejection.

This was the procedure followed after Denmark rejected the Maastricht Treaty in a 1992 referendum.