The Taoiseach and Tánaiste have made final appeals for a Yes vote in tomorrow's referendum, with Mr Ahern describing polling day as "a date with history" for Ireland and Europe.
Outlining his case for the last time in the campaign, the Taoiseach said a Yes vote would give the strongest protection to neutrality; give other countries the opportunities Ireland had; protect and expand employment; and keep Ireland at the heart of the EU.
"Thirty years ago the Irish people put their faith in a future of partnership with Europe," he said. "Their faith has been repaid time and again."
He said he fully appreciated that the campaign of "charge and counter-charge" had confused many people. However, it was clear that people who supported enlargement, who believed Europe was important for the economy and those who supported neutrality should vote Yes.
He appealed to voters to turn out, saying the Nice Treaty was "a vital issue for this country and a vital issue for Europe".
He said he had yet to hear a credible argument about the economic benefits of a No vote.
The campaign poster urging people to vote No to protect neutrality was "an absolute untruth", Mr Ahern said. "Anyone who says you are protecting Irish neutrality by voting No is not telling the truth." The Taoiseach maintained that by Sunday, "the Irish people will understand the Treaty of Nice, what enhanced co-operation means, what qualified majority voting means, probably better than people anywhere else".
He brushed aside a question as to whether a defeat would be damaging to him politically. "I'm not important in this. The important thing is that the country continues to play a vital part in Europe. Bertie Ahern is not important in this issue. The future of the country is what is important."
Ms Harney said the Nice Treaty was simply a means of changing EU rules to allow up to 12 new countries to join. "Ten countries are now ready. They want to join in January 2004. We all agree they are ready to join in January 2004. And if we vote Yes they will join in January 2004. So if you favour enlargement, vote Yes."
She said Ireland should not stand in the way of others. "We have never delayed anyone's progress and we have never said we know what's best for them."
A No vote would leave Ireland "explaining what it meant and didn't mean for Ireland and Europe, instead of getting on with the job of selling good news about Ireland as a location for new jobs and investment".
Her party colleague, Ms Liz O'Donnell, appealed to women voters who had fears about neutrality to vote Yes. She said she had met women who feared their sons might be forced into some future war without any democratic control from Ireland.
"I wouldn't vote Yes if that was the case," she said.