Sinn Féin president Gerry Adams admitted last night he had only made up his mind on support for the new policing arrangements within the past two months.
He told a packed public meeting in Newcastle be believed what he called "strategic advance" required a deal on policing. He also said that such a deal had to be acceptable to republicans.
Referring to today's publication of the Policing Ombudsman's report into RUC-loyalist collusion, he argued that such collusion was another reason for joining policing structures.
"No-one should be able to do that again to any one of our people," he added.
Sinn Féin policing spokesman Gerry Kelly also spoke on strategic terms and said that conflicts are resolved either through outright victory and defeat or across the negotiating table.
Policing policy was to be seen in that light, and he laid out in detail Sinn Féin's beliefs that sufficient progress had been made on the separation of the police and British intelligence service MI5, the use of plastic bullets, Diplock non-jury courts and a timetable for transfer of policing and justice powers sometime in 2008.
The bulk of the three-hour meeting was taken up with questions from the 300-member audience which included former prisoners and those who had been on the blanket protest in the Maze prison.
Some speakers, while backing Sinn Féin's overall political strategy, voiced opposition to the proposed tactical move and declared they could support neither the PSNI nor the Garda.
The meeting was also addressed by Dominic McEvoy who was charged in connection with the Northern Bank robbery but has since had charges against him dropped. He urged the party to root out the unacceptable elements within the PSNI.
To those who expressed outright opposition to the Sinn Féin strategy, he challenged them to produce an alternative.