The Taoiseach, Mr Ahern, and the Fine Gael leader, Mr Bruton, are locked in a bitter war of words over what Mr Ahern did or did not say about detention centres for asylum-seekers on his recent visit to Australia.
In a strongly-worded statement, a clearly angry Mr Ahern last night described Mr Bruton's claim that he was exploiting the immigration issue for political gain as "one of the most cynical statements by a leader of the Opposition in recent years".
The standoff between the two men on the controversy is set to continue next week, when the Taoiseach will face Dail questions about his visit to Australia.
The fact that Mr Bruton used the Lisbon EU summit to call on other European leaders to condemn him has particularly angered the Taoiseach. He said the Opposition "conspiracy theory" that he had manipulated the public towards believing that he advocated the use of detention centres was "so ludicrous as to be almost bizarre".
However, Mr Bruton refused to climb down last night, saying that Mr Ahern's comments were an attempt to "rewrite the history of the carefully-choreographed commentary on the immigration issue during his visit to Australia".
Mr Bruton said that the Taoiseach had created the controversy himself by his deliberate choice to make immigration an issue during the trip and, instead of apologising for his "irresponsibility", he was now trying to blame everybody else.
In Lisbon on Thursday, while attending a meeting of the European People's Party, Mr Bruton called on the EU summit to condemn politicians who exploited the immigration issue and claimed that the Taoiseach had done this.
Speaking in his constituency on his return from Lisbon, the Taoiseach said that in his attempt to inflict damage on him Mr Bruton had resorted to using "imported methods of negative campaigning".
The Taoiseach said: "By building misrepresentations upon misrepresentations, promoting conspiracies as serious comment, never seeking balance and always using extreme denunciations, he has chosen to play politics with immigration in an unprecedented and damaging way."
Mr Ahern said he wanted to make it clear that he did not visit a detention centre and had not praised such facilities. "These comments demonstrate very clearly an opposition actively seeking to manufacture a political storm."
Explaining how he had come to be asked about the immigration issue and detention centres at two media briefings after visiting a migrant resource centre at Campsie, near Sydney, Mr Ahern conceded that he might not have responded as he should. "Now that I appreciate the scale and nature of the misrepresentations concerning Campsie, I can see that I should have specifically addressed the issue of detention centres rather than giving a general response."
The theory that he had proposed detention centres, but maintained "deniability" at the same time, was "simple, plain, unqualified nonsense".
Mr Ahern said he had asked for additional events to be included on his Australian itinerary, including visits to an integrated school and to a facility which would provide him with an insight into multicultural and integration issues in Australia.
He had been "incredibly impressed" by the work of the Campsie migrant centre and was convinced that we needed similar facilities in Ireland. "That is what I was saying on Monday 13th when commenting on how the Australian system was viewed as excellent. These comments about what I saw were presented by the Opposition as an endorsement of detention centres, which I didn't comment on and didn't visit."