Sinn Fein will "campaign vigorously" against the implementation plan for the new Police Service of Northern Ireland.
The Methodist Church yesterday joined the SDLP, the Catholic bishops and both governments in endorsing it.
At a press conference, however, Sinn Fein released its detailed objections to the policing implementation plan. The party chairman, Mr Mitchel McLaughlin, said: "We will not be recommending that people join the Policing Board. Sinn Fein will campaign vigorously to ensure that there is an informed debate against these proposals.
"Sinn Fein will argue that nationalists and republicans in these circumstances cannot possibly endorse this as a new beginning to policing because it falls so dramatically short of Patten in key and substantive areas."
Asked what effect it would have if the GAA followed the example of the SDLP and the Catholic Church and endorsed the plan, Mr McLaughlin said: "The media coming at this on the basis that the GAA has to make a choice between Sinn Fein and the SDLP does a great disservice to the GAA, as an organisation which has demonstrated skill in avoiding becoming embroiled in political controversy."
He said: "We will campaign in terms of protest activity, in terms of community forums. We want to have debates. We would like very much the SDLP to come and share the platforms with us. This will be open democratic, peaceful and well organised.
"Let people explain that the human rights abusers who are in the RUC can simply transfer to this new police service, that is corrupted at the very beginning and there are no powers at board level to weed them back out again."
The Sinn Fein MLA, Mr Francie Molloy, said: "We remind people at this time that the SDLP in the past did a similar exercise in relation to recruiting for the UDR.
"We know where that brought us, we know the results of the recruitment of the UDR, and it took us years to get rid of that particular force, a force that was riddled with collusion with loyalist paramilitaries."
Also yesterday the Association of SDLP Councillors pledged its support for the party's leadership decision to nominate members to the new Policing Board.
The association's chairman, Mr Patsy McGlone, said his party had worked "consistently through dark and difficult days" to ensure that an acceptable police service could come into being.
"Our decision to enter into the new arrangements and endorse the new service is a welcome move, especially in the context of our successful campaign to secure the spirit and the substance of Patten," he said.
And the Methodist Church in Ireland has endorsed the policing implementation plan, saying it was addressing its concerns regarding the name, title and badge, the oath, the Policing Board, recruitment procedures and redundancies.
"We acknowledge that the best, if difficult, way to reach a final decision to the unresolved concerns now is through the Policing Board as is recommended," it said.
The Methodists also called on serving police officers to demonstrate their commitment to the plan's human rights dimension by voluntarily endorsing the new oath.