Fianna Fáil leader Micheál Martin has launched a strong attack on Sinn Féin and firmly ruled out a coalition with the party after the next election.
“I have made this repeatedly clear,’’ he added.
He said the failure of Gerry Adams and Sinn Féin to dissociate themselves from the Provisional IRA was unacceptable.
Mr Martin was speaking to journalists in Arbour Hill, Dublin, on Sunday, following his oration at the party's annual commemoration of the 1916 Rising in which he referred to recent Northern Ireland investigations.
He said they had had shown there were still many appalling stories to emerge from the illegitimate campaign of the Provisional IRA.
They had yet to receive proper attention in the Dublin media, he added.
“There are still many families waiting to hear the full details of how their loved ones were condemned by masked men without reference to even basic humanity,’’ said Mr Martin.
He said the end of the Provisional IRA campaign had marked a victory for democratic republicanism on the island, which was enabled by 1916.
“The agreed future ratified by the referendums North and South recognised, for the first time in history, the right of the people of this island to decide its future,’’ he added.
“As we have learned so painfully in other areas, we cannot overcome the past by ignoring it.’’
Mr Martin said it was a sad fact one group had committed itself to an ongoing campaign of trying to sectionalise and distort the history of 1916.
“At the core of their narrative lies the claim that the hidden leadership of the Provisional movement retained the right to kill and maim in our name in spite of constant rejection,’’ he added.
“For them, it retained the right to bomb civilians, to kneecap children and to have a parallel and secret justice system devoted to covering up the crimes of their members.’’
He said they had ignored the Proclamation’s clear demand that no one who served the Republic would “dishonour it with cowardice, inhumanity or rapine’’.
To applause from those present, he said no one should be in doubt the Provisional IRA had no claim to the title of honour that was Óglaigh na hÉireann. That belonged, he said, to the men and women of the defence forces alone.
Mr Martin said the calling of an “opportunistic’’ general election by the UK government had directly undermined the ability to get the Northern institutions working.
“Stopping everything and pushing parties into another electoral contest has no positive side to it,’’ he added.
“It is obvious that this was viewed as irrelevant in comparison to Westminster party politics.’’
Mr Martin said even more important was that London was proceeding to bulldoze through its vision of a hard Brexit with no concern for the views of the majority in Northern Ireland or the impact which Brexit might have on the process of shared progress and reconciliation on the island.
“In both of these cases our Government has a duty to speak up for Ireland’s interests,’’ he added. “Six years of quietly going along with Tory neglect has to end.’’