The Minister for Foreign Affairs, Mr Cowen, today defended comments made by the Taoiseach about campaigners for a No vote in the referendum on the Nice Treaty.
Mr Ahern has been criticised for referring to the anti-Nice Treaty campaigners as "whingers". Speaking on Saturday at the EU summit in Seville, Mr Ahern also accused the No campaigners of misleading the electorate and of scaremongering.
The Opposition said Mr Ahern’s comments were inappropriate and insulting.
But speaking on RTÉ's Morning Ireland, Mr Brian Cowen said the Yes side of the debate was entitled to defend itself from attacks.
Sinn Féin has called on the Taoiseach and Mr Ahern to withdraw their "grossly offensive remarks."
"Mr Ahern is using his insulting comments to try and cloud the issues of the Nice Treaty debate, which extend far beyond neutrality," said Mr Aengus Ó Snodaigh.
"But even on neutrality his government has failed the Irish people. His declaration on neutrality is not legally binding."
The Cabinet is expected to finalise the wording for the second Nice Treaty referendum tomorrow.
The challenge facing the Yes campaigners were revealed yesterday when the PD Minister of State for Finance, Mr Tom Parlon, said he was not so sure that a constitutional referendum on neutrality would improve the case for a Yes vote.
"It may be seen to be going for an overkill," he said. PD sources played down Mr Parlon's remarks, saying that he was speaking in a personal capacity.
Mr Ahern and Mr Cowen are likely to hold further discussions with Fine Gael and Labour in advance of a final decision on the wording.
Returning from Seville, Mr Ahern insisted that the two declarations agreed there on Ireland's military neutrality would remove that issue from the coming debate.
However, Mr Ahern's reference to "whingeing" among No campaigners has caused some concern in the pro-referendum lobby that he might have conceded vital ground.