DUP leader Ian Paisley has warned that the St Andrews Agreement is "far from a done deal" and that unionists will not share power with republicans on trust alone.
Sinn Féin and the SDLP yesterday announced intensive consultations with the party grassroots on the St Andrews Agreement agreed last week.
"The DUP demands delivery," Dr Paisley said. "If there is no delivery, then there is no deal."
He issued his warning after a visit to his North Antrim constituency by Minister for Foreign Affairs Dermot Ahern, who said that current difficulties could be "fixed up reasonably soon if there is willingness on both sides".
Mr Ahern said the governments were continuing "intensive discussions with the parties" to unravel the difficulties which emerged earlier this week and that led to the postponement of the first official meeting between Dr Paisley and Sinn Féin president Gerry Adams at Stormont on Tuesday.
In Ballymena, Mr Ahern referred to the republican position on policing and the requirement for acceptance of the PSNI to enable the restoration of the Stormont institutions. People want to move on in relation to policing," he said.
"They accept that huge reform has taken place as a result of Patten. It's one of the most reformed police services in the western world.
"The time is now for moving on, and hopefully over the next few weeks decisions will be made by Sinn Féin which will lead to devolved government." He said the two governments' timetable leading to devolution by March 26th can and will be met, "if there's a willingness".
Dr Paisley said his party would not finalise its position on the St Andrews Agreement "until we [ have] carried out our pledge to consult widely with the party and the community. This consultation has now begun."
He added that important aspects of the St Andrews Agreement, such as the institutions and structures of evolved government, a financial package "and equality and fairness measures for the unionist people, require more effort". The importance of policing should not be underestimated, he added.
"If Sinn Féin is having difficulties in getting their people to support the police, then they should go to the government and ask for more time, because there is no question of the DUP accepting anything less than their full support for the rule of law."
Newry and Armagh MP Conor Murphy said Sinn Féin's consultation on the St Andrews proposals would be "exhaustive" but would "not drag on". Sinn Féin has appointed Mr Murphy, Mary Lou McDonald and Martin Ferris to oversee the consultation.
Mr Murphy said in Belfast: "Next week party activists will come together in Newry for a major all-Ireland conference. Contributions will be made by academics and other outside bodies. This consultation is not simply about policing. . . It is to establish whether or not the package agreed by the two governments last week has the potential to see the political institutions reformed and the other outstanding matters resolved.
"There are clearly challenges ahead for all of the parties, but as we said last week at St Andrews, none of these are obstacles which cannot be overcome if the necessary political will is displayed."