The parents of IRA murder victim Paul Quinn will today tell TDs they are "deeply disappointed" in Mary Lou McDonald's response to their justice campaign.
Breege Quinn told the Belfast Telegraph she was very hurt that the Sinn Fein president did not respond when a party supporter told a rally in Newry that Finance Minister Conor Murphy had no need to apologise for calling Paul a criminal.
There was warm applause from the crowd to the comments by 'Kevin from Crossmaglen' at the Sinn Fein meeting last week.
Mrs Quinn said: "Mary Lou let his remarks go unchallenged. This flies in the face of the phone conversation I had with her just a few weeks ago.
"She said that, as a mother, she understood my suffering. If she understood, she would have challenged 'Kevin from Crossmaglen'. Instead, she remained silent.
"To say we are disappointed is an understatement. I can't describe the hurt and humiliation we felt when we heard those words applauded at a political rally, yet, we are the ones accused of making Paul's murder political."
Mrs Quinn said that she and her husband Stephen were emotionally exhausted by their justice campaign.
"This last week has been a difficult one, but it has strengthened our resolve. We will keep on fighting for our son. We are not going away," she added. Mrs Quinn said that she would not be placated by "obscure apologies and gestures" from Mr Murphy and Ms McDonald. She also claimed that the slur that Paul was a criminal was being "actively promoted" by Sinn Fein supporters.
Mrs Quinn said: "Stephen and I are very pleased to get the chance to go to the Dail and talk to the parties. We have been there before and our message is clear and consistent.
"The idea that Paul's murder was just an election issue is insulting. We have lived with loss for 13 years and we have hungered for justice from the moment he was taken from us.
"We again repeat our call for Conor Murphy to say the simple words that Paul Quinn was not a criminal and to go to the PSNI and Garda with the names of the IRA men he spoke to in Cullyhanna. We won't meet Sinn Fein until he does so."
Crossmaglen SDLP councillor Pete Byrne, who is accompanying the Quinns to the Dail, added: "I will be there to give my full support to Breege and Stephen as they call on Mary Lou McDonald to do the right thing and as they ask Conor Murphy to clearly state that Paul wasn't a criminal."
The Finance Minister made his controversial remarks weeks after the 2007 murder. He then denied making them until footage of his BBC interview was unearthed. He apologised last month but has refused to say that Paul wasn't a criminal.
The 21-year-old Cullyhanna man was beaten to death by the IRA in a barn in Co Monaghan.
At the time of the murder, Mr Murphy said he had spoken to the IRA and was satisfied it was not involved.