The Rev Ian Paisley has said Sinn Féin must 'deliver' on today's historic shift in policy on support for the PSNI.
Anything less than full implementation of Sinn Fein's commitments would render today's meeting "valueless," he said.
"The DUP has forced Sinn Féin to recognise support for the police and the rule of law as an issue of paramount importance for which there can be no other way. Sinn Féin must now walk this road. "No post-dated action can take the place of real delivery.
The postponements must come to an end. "The time for true, visible and open support for the police and law enforcement has arrived."
Today's shift means telling police about crime, taking seats on accountability bodies like the Policing Board and District Policing Partnerships.
"Only with real delivery can the way be cleared for a full return to democracy and a facing up to the everyday needs and requirements of the people of Northern Ireland," he said.
"The site must be cleared before proper building can begin. All Ulster people, across both the religious and political divides, know that it is now or never."
The DUP, the majority unionist party, will be expected to share power with Sinn Féin by the time the Northern Ireland Assembly and Executive is restored on March 26.
That was part of the deal agreed last October by the Irish and British Governments at St Andrews in Scotland.