There were heated exchanges as Sinn Féin backed a Government motion setting up a tribunal of inquiry into the murder of two RUC officers.
Minister for Justice Michael McDowell said the tribunal would inquire "into suggestions of collusion in the brutal and callous murders of RUC Chief Supt Harry Breen and RUC Supt Bob Buchanan by the Provisional IRA in 1989".
Mr McDowell said he had full confidence that the Garda, as well as any other institution of the State, would be forthcoming in its engagement with the tribunal.
"There is, however, one organisation that could provide full answers to the tribunal and that, of course, is the IRA," he added.
Sinn Féin and the IRA could not have it both ways, he said. "They cannot clamour for justice and truth regarding other barbaric acts that Judge Cory has reported on and in respect of which he has recommended tribunals and not co-operate with this one," Mr McDowell added.
Sinn Féin's Dáil leader, Caoimhghín Ó Caoláin, said his party was in favour of a process of truth recovery but criticised the absence of public inquiries into the murder of Pat Finucane, the Dublin and Monaghan bombings, and other incidents.
"There has been an attempt by the Minister for Justice, by his fellow unionists and by sections of the media to equate the alleged collusion of a garda in the killing of these two RUC officers with the widespread and systematic collusion between British forces, including the RUC, and the loyalist paramilitaries," he added.
Replying, Mr McDowell said: "I am an Irish republican and I know what Irish republicanism means. It does not involve, in this day and age, killing, shooting or bombing anybody, robbing banks, breaking people's legs or extorting money."
Martin Ferris (SF, Kerry North) said that Toby Harnden was one of the sources for the claims that there was collusion involving members of the Garda in the killings.
"He has already been castigated by Judge Peter Cory for failing to substantiate that claim. Cory said his interviews with both Harnden and Kevin Myers revealed how little these gentlemen relied on fact and how much on suspicion and hearsay," Mr Ferris added. "Harnden has already been found to have made an unsubstantiated allegation that those killed oBloody Sunday in Derry had been involved in violence that day.
"It would appear that Harnden distorted a statement given to him by one of the paratroopers involved in that event. Kevin Myers, who repeated the allegations made by Harnden, has already reacted in his usual manner, by attacking Cory, comparing him to Homer Simpson.
"There has been speculation that both Myers and Harnden will attempt to avoid giving evidence to the tribunal, further proof of the shallow nature of their claims."
