The Taoiseach clarified his remarks made at the Seville summit about "whingeing" anti-Nice activists.

Under sustained Opposition pressure at Question Time, Mr Ahern said he appreciated the work of everybody, including the No side, involved in the National Forum or Europe.

"However, I do not appreciate the fact that people ignore the leaders and senior figures of other countries who come here and represent the case of their people and strongly articulate their views on why they want the Nice Treaty passed."

Earlier, the Labour leader, Mr Ruairí Quinn, asked Mr Ahern if he was intent on losing the next referendum on the treaty. "Will he explain to the House the reason he denigrated Irish citizens who happen to have a different point of view to his own?"

The Fine Gael leader, Mr Enda Kenny, claimed the Taoiseach had branded everyone who voted No a whinger. He suggested Mr Ahern withdraw the remark "not because of issues related to the treaty per se but because of difficulties with the interpretation and legal implementation of directives and regulations by the Government". The Taoiseach, he added, should recognise that they voted against it because of legitimate concerns.

Mr Ahern replied: "I advocated from the start that the National Forum for Europe address the legitimate concerns of the people. Research and political judgment have shown that the forum is engaged in that. Deputy Kenny will appreciate that I cannot withdraw a remark I did not make."

Later, during a debate on the Seville summit, Mr Ahern said the decision to hold another referendum on the treaty was not taken lightly.

"We recognise that there are those who strongly and genuinely believe that the outcome of last year's referendum should be accepted as representing the definitive view of the people on the Treaty of Nice.

"However, for many reasons, we do not believe that any responsible government could let the matter rest there. We made this clear in our party manifestos before the general election and we made this clear in our agreed Programme for Government. Simply put, the Government cannot take risks about Ireland's future."

Mr Ahern said that the Seville Declarations had confirmed that the treaty posed no threat to the State's traditional policy of military neutrality. "These declarations bring timely clarity in an area which has frequently been the subject of considerable misunderstanding and misinformation."

He added that both declarations had formal status and authority.

"Should the people decide in a future referendum that the State may ratify the Treaty of Nice, our National Declaration will be associated with Ireland's instrument of ratification and it will also be registered at the United Nations."

Mr Ahern said the priority going to Seville was to secure agreement of partners to the declarations. "Our success on this issue at Seville opened the way to the Government today deciding to hold a second referendum on the Treaty of Nice in the autumn of this year."