SINN Fein's Mary Lou McDonald has been dragged into defending the IRA's killing of police officers north of the Border.
The party's deputy leader said there was a "clear distinction" between the IRA killing gardai and killing RUC officers during the Troubles.
Ms McDonald's hardline stance is significant because it could damage her reputation as the fresh face of Sinn Fein, with no historical baggage of association with the IRA.
The Dublin Central TD is also resorting to the role of an IRA apologist.
Gerry Adams's belated apology to the families of Detective Garda Jerry McCabe and other members of An Garda Siochana and Army killed by the IRA has prompted calls to extend his apology to RUC victims.
But Sinn Fein has said that killing RUC officers was "vastly different" to killing gardai. According to Ms McDonald, there is a "clear distinction".
Sinn Fein general secretary Mitchell McLaughlin rejected the calls in Northern Ireland for an apology to the families of RUC members and his position has now been backed up by Ms McDonald.
"In terms of a distinction between An Garda Siochana and the RUC – as it was – he is correct. He (Mr McLaughlin) is absolutely correct in saying that," she said.
However, Fianna Fail has said that Sinn Fein's "hard neck is breathtaking". The party's justice spokesman Niall Collins said it was not acceptable for a political party to be taking such a stance.
He said it was despicable to see Mr Adams engage in "a brazen act of hypocrisy" in trying to "cleanse his political pedigree" by apologising for the killing of Det Garda McCabe.
"He was hijacking the expressions of sympathy for Adrian Donohoe," said Mr Collins.
Ms McDonald said she believed that every life lost in what she described as "the conflict" was a tragedy both for those who died and for their families.
She said: "I think what Mitchell (McLaughlin) is identifying is the clear distinction between the RUC, the British Army, the loyalist paramilitaries, the IRA – all of whom were combatants in a conflict up in the North over decades and decades – and then An Garda Siochana, who clearly were not. I think that's a crucial distinction.
"It's a point, I know that Gerry (Adams) and others have made in the past and I think it holds true."
Ms McDonald explained that she wasn't saying there would never be such an apology, but that this would have to be part of a wider "process of healing" with apologies on all sides.
She added: "Bear in mind nationalists were also killed – the RUC, the British State forces, the loyalist paramilitaries also inflicted harm.
"We need to find a way that we get to the point where a full apology on all sides is made and a genuine apology.
"But for that to actually happen, we need to have vast, wide-ranging conversations and a process to mediate all this."