The DUP does not expect a shadow First Minister and Deputy First Minister to be chosen by a restored Assembly on November 24th, Peter Robinson has said.
The party deputy leader believes "there is every indication that Sinn Féin will not be ready" and he doubted republican willingness to call a special ardfheis to assent to backing the police, courts and the rule of law.
Citing the DUP's ability to call its membership at short notice to discuss the St Andrews Agreement, Mr Robinson said: "Perhaps we are more capable logistically than the republicans. I rather suspect that if they had the will to do it, they could have their ardfheis, they could have their decision taken," he told BBC Radio Ulster at the weekend.
Republicans could take all the time they needed, he added, warning that the DUP would not move on anything without what he called "upfront delivery" on policing from Sinn Féin.
The two main unionist and nationalist parties remain at loggerheads over the question of a pledge of office to be taken by shadow ministers elected by the Assembly on November if the two governments' plan for restoration runs to plan.
The DUP is demanding, among other things, that any republican nominee to the post of Deputy First Minister pledge support for the PSNI and the administration of justice.
Sinn Féin says it cannot pre-empt a special ardfheis needed to revise the position on support for the police. Government officials are continuing to meet party representatives amid an atmosphere of growing frustration in London and Dublin at the intractability of the problem.
Republican sources suggest an ardfheis has to have details of the devolution of police and justice powers to enable an ardfheis debate to take place. Mr Adams hit back at the DUP yesterday saying Mr Robinson's remarks were "entirely predictable".
"When the DUP put up its entirely bogus demand that Sinn Féin take an 'oath of loyalty to the PSNI before the nomination of the First and Deputy First Ministers designate', many in the Sinn Féin leadership said this was really only an excuse to forestall those appointments."
The Sinn Féin president said his party was conscious of the difficulties facing the DUP.
"But Ian Paisley will not overcome these difficulties by creating new ones. It was never going to be easy to bring rejectionist unionists into a better place. Sinn Féin is not naive on these matters. But we will persist with this task."
The SDLP last night dismissed the difficulties between the DUP and Sinn Féin and called on both parties to heed the will of the electorate.
South Down Assembly member Margaret Ritchie said: "There is absolutely no reason why we cannot meet the deadline to get a First Minister and Deputy First Minister elected next month. All it requires is for Sinn Féin and the DUP to live up to what the people of Ireland signed up for 1998 - a lawful society and an inclusive democracy."