The Democratic Unionist Party has ruled out devolution of policing and justice to the Northern Ireland Assembly by next May.
Senior party member Nigel Dodds said there needed to be confidence among unionists that the structures of the IRA had been dismantled.
Northern Ireland Secretary Shaun Woodward has placed work towards the deadline at the top of his priorities after the date was was highlighted in the St Andrews Agreement paving the way to power-sharing.
Sinn Féin have pressed for quick action and believe no hurdles remain.
North Belfast MP Mr Dodds said: "The DUP has never signed up to the May 2008 target date or any other date. That is a date set by the Government and doesn't bind us.
"We have consistently argued that there can be no transfer of any powers relating to policing until there is the necessary confidence and support within the community."
A cross-party Assembly committee has been established to work towards the May date, headed by the DUP's Jeffrey Donaldson.
On Monday Mr Woodward said his key aim was encouraging dialogue towards the May deadline but added the decision would be for the Assembly and local people.
Devolution of policing and justice was a key demand of Sinn Féin, an incentive in the deal which saw them agree to work with the police earlier this year.
However, Mr Dodds, enterprise minister in the Stormont Executive, added: "The pressure must and will be maintained on republicans.
"The ball is firmly in the Sinn Féin camp and they need to deliver and deliver quickly."
A spokesman for Sinn Féin said all parties had agreed to the May date at St Andrews.
"It is very clear on the timetable for policing and justice and we expect that timetable to be kept," he said. "Sinn Féin have never had any hurdles to overcome, our community doesn't have to overcome hurdles for anybody."