The Labour party's Alan Kelly has dubbed comments made by Sinn Fein's Northern Ireland leader about Mairia Cahill's rape allegations as "scandalous" and "outrageous".
Michelle O'Neill declined to state clearly last week whether she believed Ms Cahill.
Ms O'Neill was asked twice in a BBC interview if she believed Ms Cahill's account of the alleged abuse she said she suffered by an alleged IRA member and her claims of a cover-up by the Republican movement.
In the interview Ms O'Neill said: "It's not for me to say that I believe her."
Speaking outside Leinster House on Tuesday Mr Kelly said: "Michelle O'Neill's comments were scandalous. I thought they were outrageous for someone in her position to say that effectively she didn't believe Mairia Cahill."
The Tipperary TD added: "The fact that Sinn Fein as an organisation, given its past, are not willing to own up and acknowledge the hurt, distress that was caused to this very brave woman is, frankly, speaks to what type of an organisation they are and why we should always question whether an organisation like that should ever be let near the levers of power or government."
Mr Kelly reiterated his call for Sinn Fein president Mary Lou McDonald to "sit down with Maria Cahill face to face and apologise on behalf of the organisation".
He added that even if it took hours, Ms McDonald should sit down and listen to what Ms Cahill had to say to her.
Earlier this month, Police Ombudsman Dr Michael Maguire delivered a scathing critique into police failings, and also noted that Sinn Fein did not act when Ms Cahill originally made her allegations to senior party figures in 1997, instead waiting for three years to suspend her alleged attacker.
The Sinn Fein leader unreservedly apologised to Ms Cahill in the wake of the probe.
She said Sinn Fein now had "robust procedures in place" for mandatory reporting of abuse allegations and that she regretted that such procedures were not in place at the time Ms Cahill made her allegations.
But Ms Cahill criticised Ms McDonald's statement saying she did not go far enough.
The SDLP councillor has claimed Sinn Fein covered up her allegations against one of its members.
Ms Cahill, a grand-niece of prominent Belfast republican Joe Cahill, claimed she was sexually abused as a 16-year-old by alleged IRA member Martin Morris.
Mr Morris, who denied all wrongdoing, was later acquitted of rape when the case against him collapsed.
Ms Cahill had alleged the republican movement's response to her claims was to subject her to an IRA interrogation.
She also accused Sinn Fein of engaging in a cover-up and waging a campaign to question her integrity ever since she waived her right to anonymity.