Ian Paisley told Sinn Féin leaders tonight to ask the British government for more time if they were having difficulties getting their members to support the police in the North.
The Democratic Unionist Party leader has made backing for the Police Service the key condition on them going into a power-sharing administration with the republicans.
Sinn Féin has launched a consultation exercise within its ranks but policing spokesman Gerry Kelly MLA has warned the party had not yet got to the point where it can go to a special party conference and recommend support.
However, by November 10 the party needs to be in a position for its nominee as deputy first minister to be able to take an oath supporting police.
Mr Paisley told them: "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.''
He added: "The importance of the issue of policing should not be underestimated. Nothing can be done until there is delivery on policing.
"Sinn Féin must demonstrate its support for the police before anything happens."