Ireland would "cut ourselves apart" from the European Union if there is a No vote in next year's referendum on the EU reform treaty, the Taoiseach has warned.
The treaty document was signed together in Lisbon yesterday by 26 of the 27 EU leaders. British prime minister Gordon Brown arrived late and signed it alone.
Speaking in Lisbon, Bertie Ahern emphasised the importance of the referendum. "Our view is that we have to win it. It is in the interests of the country, the citizens of Ireland."
If passed by the people, it would mean an end to the EU's seemingly endless debate about how it should decide matters, so that it can concentrate on what issues it should tackle, such as climate change, he said.
Acknowledging that some voters may be tired of EU issues, Mr Ahern said Ireland's Constitution gives them "a real participation and involvement that they don't have in other countries".
He told The Irish Times: "I know people can find that it is not the most exciting or interesting thing but it is hugely important for the country, for the citizens of the country."
The treaty must be ratified by all member states by January 2009.
Denmark, one of the EU's most Eurosceptic states, has already decided that it does not need to hold a referendum. Portugal has yet to decide.
The Government has yet to settle on a date for the referendum, partly because it does not yet know if an all-party agreement on the wording for a children's rights referendum can be reached.
Mr Ahern is minded to hold the two on the same day, though the odds of them running separately will increase if there is any danger that the EU issue could be held over until the autumn, which he does not want.
Independent TD Finian McGrath said in Dublin yesterday that he would be opposing the Lisbon treaty and that this was outside the terms of his agreement to support the Government, which was concerned with other issues.
The Dublin North-Central TD was speaking at a press conference organised by the People's Movement/Gluaiseacht an Phobail, a broad alliance of mainly left-wing groups and individuals, which launched its campaign against the treaty yesterday.
If passed, the treaty would simplify EU decision-making in the club of 27, make qualified majority voting more common and lead to the appointment of an EU president.
The European Commission would win powers to launch EU initiatives on crime, terrorism and other issues, although Ireland has opted out for now of letting Brussels take the lead on judicial co-operation.
The battle to win the referendum has begun to take shape, following the launch yesterday of the No campaign and also the creation of a pro-Yes vote lobby group on Wednesday.
Asked about what effects a rejection of the referendum would have, Mr Ahern, who was accompanied by Minister for Foreign Affairs Dermot Ahern, said: "The implications are quite simple. We would cut ourselves apart from Europe and put ourselves apart from being a part of the decision-making process of Europe, and all that that entails into the wider world.
"It would be an enormously retrograde step for Ireland in every way. There is no sector of Irish society that would not be dramatically affected in a negative way if we vote No," he warned.
European Commission president José Manuel Barroso said EU leaders had "shown courage in their determination" to agree the treaty and now should "show the same determination" to ratify it.
The EU must be "united and strong" and be more capable "of acting in a powerful way" if it is to lead the fight to slow climate change and to make globalisation of benefit to all EU citizens, said Mr Barroso.
