The mother of IRA murder victim Paul Quinn has said Mary Lou McDonald is to ask Sinn Fein minister Conor Murphy to publicly state that her son wasn't a criminal.
reege Quinn said she had a "positive and respectful" conversation with the Sinn Fein president, who telephoned her at her Cullyhanna home on Thursday night.
She told Ms McDonald that she was "exhausted" fighting for justice for her son.
She said that the Sinn Fein president asked her to meet Mr Murphy but that she refused to do so until he publicly stated that Paul wasn't a criminal.
"I told Mary Lou I wanted her to ask Conor to do that. I am hopeful that she will ask him," Mrs Quinn said.
There are increasing calls for the Finance Minister to resign, with a range of unionist politicians saying that his position is untenable in light of his response to the Quinn murder.
The Ulster Unionists and the TUV said he must step down.
DUP leader Arlene Foster has not repeated that call but on Thursday DUP MP Sammy Wilson said Mr Murphy should quit or be sacked.
Other DUP representatives also appear to have broken ranks to declare that Mr Murphy should go.
The Quinn family have called for him to resign but Ms McDonald has said there is "no question" of him doing so.
Paul Quinn was beaten to death by an IRA gang in a barn in Oram, Co Monaghan, in 2007.
Speaking after his murder, Mr Murphy said he had talked to the IRA and they told him they weren't responsible.
He condemned the killing but branded Paul a smuggler and a criminal in a television interview.
Mr Murphy denied making those remarks but, after video footage emerged this week, he apologised and retracted them.
However, Mrs Quinn said that he had side-stepped unambiguously stating that her son wasn't a criminal. "I told Mary Lou that Conor had to say that," she said.
"I thanked her for saying it and for Michelle O'Neill saying it, but I told her I needed to hear those words from Conor, that my husband Stephen and my children James and Cathy needed to hear them too.
"I told Mary Lou that I was exhausted fighting for justice for Paul for 13 years but that I had to keep going. I said that was what any mother would do and I asked her if she would do it if her son was murdered and his name blackened. 'I sure would', she said."
Mrs Quinn told the Sinn Fein president that she appreciated Mr Murphy's apology but that he needed to "clearly state that Paul wasn't a criminal".
"Mary Lou said it would be a good idea to sit at a table with Conor and talk to him," she said.
"But I told her I wouldn't do that until he said those words first." DUP MP Sammy Wilson on Thursday tweeted that Mr Murphy couldn't continue as a Stormont minister.
He said that the party was once again failing victims despite its calls for "transparency, integrity and accountability" from others. "If they have any decency, Conor Murphy should be required to resign or be sacked," he said.
DUP MLA Paul Frew, who is chairman of Mr Murphy's Assembly scrutiny committee, tweeted: "The Quinn family have lived through a tortuous period of grief at the tragic loss and murder of their son compounded by the slur, alienated by the republican movement. If the Quinn family say Conor Murphy should resign, he shouldn't have time to get his coat."
His post was retweeted by fellow MLA Jonathan Buckley and by Lisburn councillor Paul Porter. DUP leader Arlene Foster has not joined the Ulster Unionists and TUV in calling for Mr Murphy to go. Speaking at Stormont on Wednesday, she said only that his apology to the Quinns was the "right thing to do".
When asked if he should no longer be a minister, she said it was a matter for Sinn Fein.
Ulster Unionist leader Steve Aiken said that Mr Murphy's failure to state publicly that Paul Quinn wasn't a criminal was "heaping further agony" on his family.
Mr Aiken said: "In Scotland, we have seen the SNP Finance Minister resign within hours of being engulfed in scandal, yet the same doesn't apply in Northern Ireland.
"When it comes to the conduct of ministers in the Northern Ireland Executive, why do normal standards not apply as they would do across the rest of the UK or indeed the Republic of Ireland?"
The UUP leader added: "Sinn Fein's continued prevarication on this issue means that they are in no position to lecture others about respect, honesty and integrity, and definitely not when the RHI inquiry report is published.
"If the New Decade, New Approach document was meant to herald a new approach to politics in the reformed executive, Sinn Fein have failed miserably at the first hurdle."
Paul Quinn's murder, and Sinn Fein's response to it, has become a major issue in the Republic's general election campaign.
The party has faced claims that the killing and its aftermath proves that the party is unfit for government.
The 21-year-old was killed after clashing with the son of a local IRA commander. He was lured from his Cullyhanna home in south Armagh to the barn in Oram where a 12-strong gang beat him with baseball bats and nail-studded cudgels. Every major bone in his body below his neck was broken in the brutal attack in October 2007.
The family said Paul's hands were so badly broken, they couldn't hold rosary beads as he lay in his coffin.