A rejection of the Nice Treaty by Irish voters will throw the EU's enlargement effort into "a political mess", the highest-ranking Irish official in the European Commission, Mr David O'Sullivan, has warned.
"If Ireland will block this, we had better be very sure about why we are doing it. I am not saying that we can't do it. We have the power to do it," said Mr O'Sullivan, secretary general of the Commission.
Meanwhile, Ireland's European Commissioner Mr David Byrne urged voters to make up their minds about the treaty's contents, and not to be deflected by domestic political controversies.
Speaking to a group of Irish journalists in Brussels, Mr O'Sullivan repeatedly insisted that "a Plan B" did not exist to cope with the fallout that would follow a second Irish rejection of the Nice Treaty.
"If we say 'No', it reopens the Pandora's Box that was Nice. We don't know what the other 14 member-states would do, and we don't know what their domestic constituencies would do. Sometimes, we think that Ireland is the only country with a domestic political constituency," said Mr O'Sullivan, who discounted hopes that parts of the treaty could be added on to individual membership deals with new member states.
Other member-states had accepted the treaty "only with difficulty" and it cannot be taken for granted that they would accept enlargement unless future institutional rules were governed by the treaty.
"If the Treaty of Nice is not ratified, it is clear that we will have a political mess. People will not understand why Ireland has put Europe in this situation. They do not feel that there is a vital national interest threatened that would justify taking the step to block it."
Asked if Ireland's EU reputation would be damaged by a No vote on October 19th, he said: "Political goodwill is not something that is measured by the kilo, or the litre." But he said that it could not be discounted that the candidate countries will, in the years to come, remember that Ireland was not "terribly helpful" towards them as they stood on the cusp of EU membership. The European Commission will issue its assessment of the preparations carried out to date by the candidate countries in Central and Eastern European countries, along with Cyprus and Malta next week.
However, Mr O'Sullivan emphasised the sacrifices they have made. "They have sweated their guts out to get to this stage. The amount of political pain that they have taken to sign up has been huge.
"Frankly, they are getting a little impatient. But if there is any country that has not done its homework then we will say so. But it is likely that we will say that the bulk of them have done their homework," he said.
Enlargement offers the chance "the lay the ghosts of Yalta", said Mr O'Sullivan, who previously served as chef de cabinet to Commission president, Mr Romano Prodi. "The stakes are huge. Enlargement is more historic than the Treaty of Rome," he added.
Questioned repeatedly about the plans to cut the number of Commissioners once the EU has 27 members, Mr O'Sullivan insisted countries not at the table would not lose out. The Brussels system does not work on "a zero-sum game", he said.
"We spend a lot of time here trying to ensure that it is a win-win for all member-states. It doesn't work the other way."
The Irish Government had defended its own interests well at Nice. "I have to say that they negotiated well even if they negotiated against the Commission's position, particularly on tax harmonisation," he said.
Commissioner Byrne said he had noted warnings from the candidate countries that they would take "a long time to forget" an Irish 'No' vote. "I must say that that struck fear into my heart," he said.
Dealing with the impact of domestic political controversies on the referendum, he said the Irish Small and Medium Enterprises Association has warned that some of their members might vote No because of high Irish insurance costs. "I find that absolutely shocking," he said, adding that such issues had nothing to do with the EU.
Mr Byrne said the Green Party in Ireland were the only Greens in Europe to oppose the treaty.
