Sinn Fein's Mitchel McLaughlin has rejected calls to resign over remarks he made about an IRA murder victim.
Jean McConville was abducted in 1972
The party chairman said the killing of Jean McConville - one of the Disappeared - was not a criminal act.
Her family have criticised the comments, which were made on a current affairs programme on Irish state broadcaster RTE.
Fianna Fail TD for Cavan-Monaghan, Brendan Smith, has called on Mr McLaughlin to retract the remarks.
The Sinn Fein member also agreed with a remark that the IRA was "the only legitimate government of Ireland".
Mrs McConville, from west Belfast, was abducted and murdered by the IRA after she went to the aid of a fatally wounded British soldier outside her front door in 1972.
The 37-year-old was one of the nine so-called Disappeared people who were murdered by the IRA and secretly buried during the 1970s.
The mother-of-10's remains were found at Shelling Hill beach in County Louth in the Irish Republic in August 2003.
The McConville family has asked Mr McLaughlin to apologise or to resign.
But speaking on BBC Radio Ulster on Wednesday, he said he would not be leaving his post.
"Of course I won't resign, I'm entitled to my view in this respect," he said.
"I didn't introduce the topic into the discussion,
"I was pressing the minister for justice on the lack of action on outstanding issues such as collusion, criminality at the heart of the British Government as far as republicans are concerned and I think, on the ropes, the minister threw in Jean McConville."
Mr Smith, co-chair of the British-Irish Parliamentary Body, described Mr McLaughlin's comments as "appalling".
They had led people to query the Sinn Fein chairman's "commitment to democratic politics, his commitment to the Good Friday Agreement", he said.
"We have a mandate - as politicians on this island - to implement the Good Friday Agreement.
"Here we have comments from a senior figure in a political organisation and it is obvious that he is not committed to making an effort to implement the will of the Irish people."
In October 2003, the IRA apologised for the grief caused to the families of the nine so-called Disappeared.
The organisation said it was sorry that the suffering of the families had continued for so long.