The Taoiseach has come in for sharp criticism from opposition parties over his remarks at the Seville Summit about "whingeing" anti-Nice activists who had "got away with hell and high water" in the last referendum campaign.
Describing Mr Ahern's comments as "inappropriate and insulting", the Labour leader, Mr Ruairí Quinn, added: "It would appear that the Taoiseach has learnt nothing from his failure to have Nice passed on the first occasion."
In a strongly-worded statement, Mr Quinn said the Taoiseach was required to "act as a persuader" for the treaty and he had to take this task seriously. "That involves convincing the Irish people that the Government have listened to their concerns since the last Nice vote and responded to them. These type of comments have no role in that process."
The Fine Gael MEP for Munster, Mr John Cushnahan, accused the Taoiseach of using "offensive language" which was no substitute for political debate. "I desperately want to see Irish voters ratify the Nice Treaty. However, I would like to disassociate myself from the remarks of the Taoiseach.
"The views of those who oppose the Treaty of Nice should be treated with respect and counteracted with concrete and cogent arguments. To describe them as whingers is arrogant, disrespectful and counter-productive," he said.
The Green Party leader, Mr Trevor Sargent, said the Taoiseach was "letting himself down by substituting insults for rational debate" on the treaty. "Bertie Ahern's curt dismissal of treaty opponents was unfortunate and has reduced what should be rational argument into a slanging match and a smear campaign."
He said the Taoiseach's "arrogant and dismissive language" was an unfair slight to No voters. "In reducing the debate to name-calling, the Taoiseach is trying to avoid real debate as to why Nice is incompatible with the Irish Constitution," Mr Sargent said.
The Sinn Féin TD for Dublin South West, Mr Seán Crowe, called on Mr Ahern to apologise for "his cheap insult to voters who not only had the right but also had the courage to disagree with the Government by saying No to Nice".
He added: "If this is the level of political sophistication and debate that we can expect from the Fianna Fáil and Fine Gael leaderships, then it looks increasingly likely that the replay of the Nice referendum will result in another defeat for an arrogant Government."
The Socialist Party TD, Mr Joe Higgins, said the Taoiseach would "do well to remember that the arrogance which the pro-Nice side displayed in the last campaign was one factor in alienating the Irish people and they will be equally unimpressed by a campaign based on abuse".
However, a light-hearted approach to the Taoiseach's remarks was taken by Mr Roger Cole of the anti-Nice Peace and Neutrality Alliance. "Mr Ahern has a good sense of humour and I'm sure he doesn't expect to be taken seriously."
Mr Cole said he would be having discussions with "likeminded people in the business world" about prospects for the establishment of a "Democratic Fund" to fund a possible Supreme Court challenge to the second Nice referendum under Article 6 of the Constitution which states: "All powers of government, legislative, executive and judicial, derive, under God, from the people, whose right it is to designate the rulers of the State and, in final appeal, to decide all questions of national policy, according to the requirements of the common good."