The Minister for Foreign Affairs has accused anti-Lisbon campaign group Libertas of 'playing the man, not the ball' in its criticism of Taoiseach Brian Cowen.
Micheál Martin urged the organisation's founder, Declan Ganley, to 'reflect' on what he is saying.
Responding to Mr Ganley's claim that the Taoiseach was using 'bully boy tactics', Minister Martin said it seemed to be an 'extraordinary outburst' by Mr Ganley.
He said the Government would continue to concentrate on the issues rather than going into personalities.
Asked about media reports linking many of the Libertas founders to Rivada, which supplies communications expertise to the US authorities, Mr Martin said it was not a matter for him.
He was speaking at a Fianna Fáil news conference on the Lisbon Treaty, during which he said the treaty would give the EU a clearer and stronger voice in the world.
Tánaiste Mary Couglan said the great majority of the Irish business community was in favour of Lisbon, which she said would make the EU more efficient and effective in the face of global competition.
Mr Ganley earlier rejected claims that there are strong links between Libertas and Rivada, which he owns.
He said the claims were an attempt to throw rocks at Libertas, to call him names and to make up stories in a shady way in order to distract from issues in the Lisbon campaign.
Mr Ganley denied there was any overlap between Libertas and Rivada. He said it was being suggested that he was doing business with the US military.
Mr Ganley's company has supplied the National Guard and Norcom and had received the Louisana Distinguished Service medal for his work in the aftermath of Hurricane Katrina.
He claimed his campaign had been the focus of bully-boy tactics from elements opposing them.
Mr Ganley said his backers were 100% Irish but did not want their identity disclosed and he added that he did not blame them.
RTÉ.ie/lisbon has complete coverage of the Lisbon Treaty