The parents of IRA murder victim Paul Quinn are to visit Stormont on Monday to raise Sinn Fein minister Conor Murphy's refusal to say their son wasn't a criminal with MLAs.
Breege and Stephen Quinn will meet representatives from every political party bar Sinn Fein.
They have said they won't meet that party until Mr Murphy unambiguously states that their son was not a criminal.
Mrs Quinn said: "We are visiting Stormont on Monday and we hope that, when we are there, Conor Murphy will be man enough to come out and say Paul wasn't a criminal.
"Mary Lou McDonald has said it. Michelle O'Neill has said it. Conor needs to find the courage to do the same.
"Why will he not speak the same words as his Sinn Fein colleagues?"
Mrs Quinn will arrive in Parliament Buildings as MLAs gather for a plenary session.
"We are delighted to have the opportunity to talk to the politicians face-to-face," she said.
"We will be appealing to them to use whatever influence they have with Conor because he hasn't listened to us so far.
"I would hope that our presence in Parliament Buildings would encourage him to look into his heart and say the words that would mean so much to us."
Mrs Quinn said that Mr Murphy had "a big job now as Finance Minister". She said: "I know that he's has a lot of things to do but he still has a responsibility to my family given the great wrong he did us in 2007.
"We appreciate what Mary Lou and Michelle have done. But it was Conor who blackened Paul's name and we need to hear those words from him."
Mrs Quinn added: "It was never about the Dail election for Stephen and me. We've been talking about Paul for 13 years, and we'll talk about him for another 13 if we have to."
Paul Quinn was beaten to death by the IRA in a barn in Oram, Co Monaghan, in 2007. The 21-year-old Cullyhanna man had previously clashed with the son of the local Provisional commander.
Following the murder Mr Murphy branded Paul a criminal and a smuggler.
He later denied making the remarks but was forced to admit them after a tape of the BBC interview was unearthed.
He retracted his comments last week and apologised but has refused the family's demand that he categorically state that Paul wasn't a criminal. Stormont's Finance Committee has written to the minister telling him that his conduct "calls into question" his fitness for office.
The letter asks him to explain why he branded Paul a criminal and why he "denied the comments for the past 13 years".
It states: "It is the committee's view that your conduct calls into question your fitness for office."
Responding to the letter, a Sinn Fein spokesman said: "When Conor Murphy took up the post of Finance Minister only weeks ago, nearly all of these parties wished him well and supported him in the role.
"And now, over the last week, they have developed serious considerations about his place in office over remarks made 13 years ago.
"Conor has written to the family, unreservedly withdrawn his remarks and apologised, and he continues to carry out the important task of Finance Minister."