Sinn Féin president Gerry Adams told a gathering of about 1,000 republicans in Newry last night that their endorsement of policing would be "a big ask".
The reception of the crowd at the Canal Court Hotel was broadly warm and welcoming to Mr Adams, who was accompanied by Newry and Armagh MP Conor Murphy, justice spokesman Gerry Kelly and MEP Bairbre de Brún.
However, one man said that for Sinn Féin to support policing would be "repulsive". He said his family had been intimidated by the B-Specials, an RUC unit known among Catholics for its reputation for brutality.
"The B-Specials pulled me and my brothers from my bed in the middle of the night. Years later, my brother was a volunteer and he was shot 17 times in the back by police and he died. I think it is repulsive for you to ask us to join the RUC, the B-Specials, the PSNI, because it's all the same.
"I thought it was bad of us to give the guns away, but in five days' time [ at the ardfheis] you want us to join them. And what you are doing is joining them and giving them a hand in controlling us. It seems nonsense."
He said no one had spoken to him about the loss of family members, Mr Adams having earlier said that party officials had consulted with the families of "patriot dead" to talk them through the move to support policing. "No one came near my family," he said.
Shortly afterwards, a female party member said: "We came and spoke to your sister yesterday." Mr Adams then told the man: "I respect everything you have said. You're not on your own. We could all give our family history about what we have lost. Like I say, to support policing is a big ask. I have suffered. I have been beaten unconscious in Springfield Road RUC barracks, I have been in Castlereagh [ interrogation centre] tons of times."
He continued: "My house has been bombed and I have been shot at and I am sure the peelers were involved. It is fair enough what you say.
"We are the leadership and we have to lead the course forward. We are going in the proper direction, taking Ireland in the right direction."
Mr Adams then told the crowd: "We will not stop until we get a united Ireland on this island."
Most of last night's speakers seemed to regard yesterday's report by Police Ombudsman Nuala O'Loan on collusion in more than a dozen murders between an Ulster Volunteer Force unit in north Belfast and RUC special branch as a reason for Sinn Féin to get involved in policing rather than continue to shun it.
"If we don't get in and join them to change the police and watch what they're doing, then what will happen?" one woman said. "We don't want the unionists and the SDLP looking after it anymore, because they can't do it."
Jimmy Carr, a community worker who was at the meeting, said he was a republican, "but not of your persuasion. I personally believe that what you are doing is 101 per cent right. If you're not in, you can't win."