Fianna Fail junior minister Mr Tom Kitt has accused Mr McCreevy of damaging Ireland's position in the EU. The Minister of State for Labour, Trade and Consumer Affairs told Mr McCreevy that he was not "in the business of kicking the EU in the shins at the moment".
But the Minister for Finance insisted the "only kicking I have seen in the last six months" was the EU kicking of himself.
Asked later if he was referring to a Cabinet Minister, Mr Kitt replied: "Well yes."
Mr Kitt decided to speak out as a former Minister of State for European Affairs who was involved in negotiations for the last round of enlargement and to support the Taoiseach and the Minister for Foreign Affairs, Mr Cowen.
He added there was a danger that we were signalling a shift in European sentiment. "The day Fianna Fail joins the rump of Conservative Eurosceptics (in Britain) is a bad day for the country and a very bad day for Fianna Fail." Mr McCreevy retorted that he had "been called a lot worse than a Eurosceptic" in his years in politics. Mr McCreevy insisted he was "one of the most committed Europeans and not just in a financial sense".
Mr Kitt said Ireland should be careful not to get itself dragged into the Eurosceptic camp where those like the British Conservative party were negative on all fronts. Ireland, he said, had to show it was well able to fight its corner.
"The Attorney General Michael McDowell has pointed out the difference between a partnership and a federalist approach. But we operate both. For example, the Belgians and French would like to impose a uniform social affairs policy but we have not allowed it to happen as we like a light regulatory system.
"On the other hand, in other areas we pool our resources, for example in employment action and trade, where we worked with 15 others in Seattle."
Mr McCreevy stuck to his comments welcoming the democratic decision of the people on the Nice vote. "When asked a question by journalists I gave my views. Nothing I said conflicts with Government policy. It caused no embarrassment. It was nothing more than what people would have expected me to say."
The Tanaiste reiterated a very pro-European line, saying she "shuddered to think" the state the economy would be in if we had not joined the euro. "Thousands of jobs are dependent on us continuing to be in the single currency."
She added that she wanted to emphasise her own and the Government's strong disappointment with the outcome of the Nice Treaty. "We will now establish the forum and take time to reflect on the Nice Treaty."
She added there could no longer be a complaint that there was no interest in Europe.
