All the families of Bloody Sunday victims have jointly issued a strong appeal to reluctant witnesses, including civilian gunmen, to come forward and co-operate with the inquiry.
Legal representatives of the 27 families yesterday announced an initiative aimed at overcoming what has previously been described by a tribunal lawyer as the "wall of silence" about IRA membership and activities on Bloody Sunday.
The tribunal has therefore postponed until Monday consideration of what its chairman, Lord Saville, termed the "quandary" in which it found itself after a crucial witness yesterday refused to name a gunman he believed he had recognised on the day.
The dilemma arose over a statement by Mr William Harley, who said he watched from his top-floor flat beside Rossville Street, in the Bogside, as a civilian gunmen fired pistol shots around a corner.
Mr Harley's statement said: "I knew him from work but I will not name him."
Yesterday Mr Christopher Clarke QC, for the tribunal, read out part of a statement supplied by another witness, Mr Anthony Coll, who has not yet been called to give evidence. The statement said: "I heard later the Official IRA acknowledged that one man fired a pistol. This was Tony Rush, who fired a couple of shots from a wall at the end of Chamberlain Street."
When Mr Harley was asked by counsel if this was the man he had seen, he declined to answer, saying: "I will not name the man, I am sorry."
The tribunal chairman, Lord Saville, asked if he could provide any reason for his position, and the witness replied: "Yes, I can. I think there are very few of us that have not some incident in our past of which we are thoroughly ashamed, and I would not be guilty of naming . . . the man who carried out that silly action. I just cannot do it."
Mr Clarke said this was somebody who fired a lethal weapon on the streets of the city in 1972. He added: "If we are to get the whole truth of what occurred on that day, we need to investigate all shots of that kind, and their circumstances and how they came to be fired, from whatever source. If we cannot find the people who did it, we cannot properly investigate the circumstances in which they did so."
Lord Saville said that the tribunal would invite all interested parties to make suggestions or comments on the quandary in which it now found itself. He said: "In considering the position, no doubt it will be borne in mind by all concerned that when we get to others who fired . . . shots from a lethal weapon on that day, there will undoubtedly arise the same problem."
He said that in this regard he was of course thinking of the soldiers, in respect of asking them what they saw and who they saw firing shots. "As well as carrying out a full, open, complete and thorough inquiry, we must also do it in a fair manner and apply the same standards to all," Lord Saville declared.
Mr Clarke intervened to say that the inquiry had a statement from a man named Tony Rush denying that he was the gunman seen in a photograph (which had been shown to the witness).
When Mr William Hoyt, one of the tribunal judges, then asked the witness to reconsider his refusal to name the civilian gunman, Mr Harley said he wished to further explain his position.
He said: "I could be mistaken. That is what holds me back. I could well be mistaken. Perhaps I only think I know who it was. It would be a terrible thing indeed if I were to name the wrong man, as apparently someone has already done.
"I would ask the tribunal to take that into consideration as my principled reason for not wanting to offer a name."
After the lunch adjournment, Mr Arthur Harvey QC, counsel for a number of families, addressed the inquiry and quoted the words used by Mr Christopher Clarke at the outset of hearings last March.
Mr Clarke had set out the tribunal's task as being to try to discover the truth - "not the truth as people would like it to be, but the truth pure and simple, however complex, painful or unacceptable . . ."
Mr Harvey said that all 27 families represented at the inquiry urged anyone who had anything to contribute to come forward and do so now. The families were deeply saddened that some individuals had not done so.
He said that all the legal representatives of the families had met over lunchtime.
He asked for a deferment until Monday, to give the families' representatives an opportunity to discuss with tribunal lawyers "methods which we believe will result in a positive action by those persons who have not come forward".
Mr Edwin Glasgow QC, for most of the soldiers, endorsed Mr Harvey's proposal, which was then agreed to by the tribunal.