Raymond McCord snr has announced he will stand as an independent candidate in the Assembly elections scheduled for March 7th.
He said yesterday he wants to press sitting North Belfast unionists Nigel Dodds and Fred Cobain on the issue of police collusion with loyalist paramilitaries.
"I am going to give the Protestant and Catholic people a chance in North Belfast to put somebody in who is not frightened to tell the truth [ about] what's going on here. This campaign will stay on until people are in jail for my son."
Reaction from the DUP and the Ulster Unionists is reported to have dismayed Mr McCord, whose initial complaint about the RUC handling of his son's murder case led to the investigation by Police Ombudsman Nuala O'Loan.
Lord Patrick Mayhew, who was Northern secretary during part of the time examined by Mrs O'Loan, denied yesterday he knew of any RUC-loyalist collusion and would have condemned it if he had. He told BBC Northern Ireland he strongly backed former chief constable Sir Ronnie Flanagan as a man of integrity.
While unionists condemned any illegality within the police as cited by the Police Ombudsman, Mr Dodds said: "It would be wrong to cast aside the sacrifices made by hundreds of RUC officers and other members of the security forces over the years as they battled against terrorism.
"Had it not been for the gallant actions of the RUC officers, the people of Northern Ireland would have been subjected to an even greater terror onslaught."
Ulster Unionist Assembly member Fred Cobain said: "Those whose agenda is hell-bent on tarnishing the memory of the RUC should not be given carte blanche to do so.
He said the UUP is concerned that "a one-sided so-called truth commission" is being created. "Who, for example, is investigating the conspiracies and sabotage of republicans during this period?" he asked.
The business committee of the Assembly is to consider holding a special meeting to discuss the O'Loan report into collusion.
SDLP Upper Bann Assembly member Dolores Kelly said a debate would acknowledge the "strength and dignity displayed by Raymond McCord snr and his family". Both Sinn Féin and the SDLP have submitted motions for debate.
The Alliance Party said unionists needed to make the distinction between RUC bravery and the need to hold to account those who acted illegally.
Dr Stephen Farry said: "Those who claim to support the police service and the rule of law need to be prepared to acknowledge the facts when officers do wrong or the system breaks down, and seek redress."
Former head of special branch Chris Albiston criticised what he called "the superficiality" of Mrs O'Loan's report and the "lack of contextualisation of what was actually happening". He said Sir Ronnie Flanagan was "a fine chief constable and a fine leader of men".