The Fine Gael leader said he was concerned at the comments by Mr Martin McGuinness of Sinn Fein that the killers of Det Garda McCabe should be able to avail of early-release provisions of the Belfast Agreement.
Mr John Bruton said: "In my view it was never envisaged that this would happen, and it was clear to people before they voted that any premature prison releases would not extend to those accused of the Adare atrocity."
Speaking in Brussels before Mr Ahern gave his reaction to the sentencing, Mr Bruton said the Taoiseach should make an authoritative interpretation of the agreement immediately: "If the agreement means something different to what we were told during the referendum campaign then there is a very heavy burden of responsibility on the Taoiseach."
Mr Bruton said he noted with concern the contention of Det Insp John Kerin that IRA intimidation of witnesses had been the main reason the murder charges against the four could not be sustained.
He said that that reality, put beside paramilitary punishment beatings, the admission that IRA arms may have been used in the Dalkey robbery, and the IRA's admission that it abducted Mr Paddy Fox, required the Taoiseach and the Garda Commissioner to state whether the IRA ceasefire was continuing.
The Taoiseach had said, ail, Mr Bruton contended, that any act of violence was a breach of the ceasefire, and the judgment on whether the ceasefire was over was a matter for the Commissioner. "That a senior garda spoke in this way of the McCabe case requires further clarification."
Mr Bruton refused to be drawn on what he saw as the political consequences for Sinn Fein of a ruling that the ceasefire was over. "Let the authorities answer my question first," he said. "I must say what needs to be said even if it is not palatable . . . Peace must be built on truth."
The intimidation of witnesses was a fundamental attack on the rule of law on which the peace process was based, he said. "I hope that by asking the question in a firm way I can get the IRA to stop."
