Ian Paisley's Democratic Unionist Party has issued a cautious response to the St Andrews Agreement, sparking off doubts that the timetable for securing power-sharing in the North by next March could slip.
Parties were given until today to agree terms after talks in Scotland drew up a roadmap for devolution.
But the DUP is blaming any delay now on Sinn Fein's refusal to back plans for policing.
It says if Sinn Fein is not ready to take the next step in this, then the DUP is not ready to commit to any aspect of power-sharing.
In a statement issued last night, after its executive met in east Belfast, the party accused republicans of backtracking over policing.
It said this has put the two governments' timetable for restoring devolution at risk.
The first major deadline facing Northern Ireland parties is November 24 when Ian Paisley and Martin McGuinness are due to be appointed Shadow First and Deputy First Ministers at Stormont.
But British and Irish Government officials have now become increasingly concerned that the impasse over Sinn Fein's move on policing could result in that deadline slipping.