The SDLP has become the first of the North's main parties to endorse the new policing proposals, which will change the name of the RUC and remove British flags and emblems from police stations.
The party said that it had received written undertakings that once the new Police Board is in place the Northern Secretary of State will move quickly to make the important symbolic changes to the police force.
The decision to nominate three members to the 19-member Police Board was taken in a unanimous vote of the SDLP parliamentary party yesterday. The motion was put by party leader Mr John Hume and seconded by the acting Deputy First Minister, Mr Seamus Mallon.
The SDLP announced its decision after the Northern Catholic bishops had issued a statement urging nationalists to support the new police force and following the endorsement of the SDLP position by the Taoiseach, Mr Ahern.
In doing so, it effectively set the agenda for the creation of the new board and the new force. The decision - which is expected to be followed by Ulster Unionist compliance in joining - means that the new board will meet the "cross-community" criteria needed for its establishment.
The SDLP document, "A New Beginning to Policing", contains 94 points covering what it says are major concessions to nationalist demands for impartiality, protection of human rights and reform of the force to make it more accountable.
The SDLP decision was welcomed by the Northern Secretary, Dr John Reid, who said: "We have embarked on a process of fundamental changes and I am pleased that the SDLP will play a direct role in taking them forward." He hoped that the other parties would reciprocate and nominate members to the Police Board by noon today - the deadline he set last week when he published the British government's proposals on policing.
The SDLP leader, Mr John Hume, said: "We will respond positively to an invitation to join the Police Board and we will be encouraging people from all sections of the community to join the new Police Service.
"The creation of the new beginning for policing is best served by participation in the Police Service and its structures and by continuing parliamentary and political efforts to secure the new beginning for policing." Mr Hume insisted that his party's decision was a crucial step in ensuring that the Belfast Agreement would be fully implemented.
Mr Mallon appealed to young nationalists and unionists to support the new Police Service. "I want to take this opportunity to say to young people in the nationalist community: `Here is an opportunity. Here is the mechanism now through which policing can be changed and changed forever more. Do not let this opportunity slip, because Patten will never be written again. We have one opportunity to get this right. Take that chance.'"
In their statement yesterday, the Northern bishops urged Catholics to support the new force and said that sufficient grounds now existed to provide real hope for a new beginning in policing. The bishops said that the time was now right for everyone seeking a Police Service which was fair, impartial and representative to "grasp the opportunity" and use their influence to achieve this.
Sinn Fein has already rejected the revised police implementation plan, which covers all 175 Patten recommendations on RUC reform.