Unionists will not accept devolution of policing and justice powers if it means the involvement of Sinn Fein in their administration, the DUP has said.
Nigel Dodds says republicans running policing is unacceptable
MP Nigel Dodds said there was no confidence in the "wider community" of Sinn Fein ministers having such powers.
He said it would be "ludicrous" if people thought they could be ministers but not support the security forces and the republican mindset must change.
"That does not mean simply taking places on the Policing Board," he said.
Sinn Fein has been demanding more reforms to policing and called for policing and justice powers to be transferred from Westminster to Stormont.
The party has refused to recommend the Police Service of Northern Ireland as a career for young Catholics or take its seats on the Policing Board which holds the force to account.
Sinn Fein's Gerry Kelly said changes were possible
On Saturday, Sinn Fein's Gerry Kelly said a new beginning to policing in Northern Ireland was possible.
Speaking at a party conference on policing, the North Belfast assembly member said if this was achieved, then republicans would have to make difficult decisions.
"Activists need to realise that we can achieve it and with achievement there comes further responsibility," he said.
"Negotiations herald change. Change brings turmoil and soul searching. It also means breaking moulds."
He said at the core of his party's position was getting "a threshold which enables the creation of democratically accountable representative civic policing and the consignment of political policing to the dustbin of history".
The SDLP's policing spokesperson, Alex Attwood said Sinn Fein should "show backbone and genuinely participate in the policing structures".
"In the forthcoming discussions, the governments must then send out one unambiguous message - now it is time, and time now, for acts of completion on policing by the provisional movement," he said.
"Nationalism is now well ahead of Sinn Fein on policing. Nationalism and everyone else cannot be held back by the tactical policing approach of Sinn Fein for narrow political reasons."