Ulster Unionist Party leader Mr David Trimble has been attacked for implying murdered solicitors Pat Finucane and Rosemary Nelson had paramilitary links.
The SDLP leader Mr Mark Durkan tonight called on Mr Trimble to withdraw the allegations. Mr Durkan said he had been contacted by Mrs Nelson's mother and wider family who expressed hurt and outrage at the UUP leader's comments.
"David Trimble's remarks were deeply offensive and utterly wrong. Hiding behind parliamentary privilege, he has questioned the good name and standing of two people who are no longer alive to respond."
Mr Trimble, who was commenting in the House of Commons on the report by Canadian Judge Peter Cory, said that while he was opposed to public inquiries, they could help uncover the truth about Mr Finucane and Mrs Nelson.
Judge Cory has recommended public inquiries into the murders of Mr Finucane, Mrs Nelson, LVF leader Billy Wright and Portadown Catholic Robert Hamill.
Mr Trimble said: "I mention those two (Finucane and Nelson) in particular because in the case of Wright a lot of his background and his terrorist activities are in the public domain and I leave out Hamill because there is no reason whatsoever to link him with others who have a clear terrorist connection."
Mr Finucane's widow Geraldine attacked Mr Trimble's comments, saying he would have to withdraw them after a public inquiry was carried out into her husband's murder. She added that Judge Cory had access to RUC files which stated that allegations that her husband had been a member of the Provisional IRA were false.
Mr Durkan said: "Today should have been about their right to truth. Instead, they have had to battle further untruths.
"David Trimble, without producing the slightest shred of evidence, has set out to blacken the reputations of Rosemary Nelson and Pat Finucane.
"It is a basic rule of any civilised society that lawyers should be free to represent their clients. Nobody should assume that lawyers hold their clients' views.
"As a lawyer, nobody should know this better than David Trimble. And yet he has gone out of his way to break this basic principle. I am calling on him to withdraw his remarks immediately and to recognise the great hurt that he has caused."