The DUP leader, Ian Paisley, has accused the Sinn Fein president, Gerry Adams, of "declaring war on law and order".
Mr. Adams had said in New York that his party could not endorse policing until authority had been transferred to Belfast from London.
Ian Paisley is becoming ever more critical of Sinn Fein.
It's for policing that he reserves his strongest words, telling republicans there's an absolute requirement that they endorse policing before they are credible for government.
There is no justification for Sinn Fein's position, he said. There can be no fudging and Gerry Adams' comments in America were in effect a declaration of war against law and order.
It is ludicrous and hypocritical for Gerry Adams, he said, to lecture the DUP about playing a full part.
There will be no surrender to those who would settle for second best.