The DUP and the other three parties in the Northern Executive appear to be on a collision course over aspects of DUP ministers' roles. After the weekly meeting of the Executive, the First Minister, Mr David Trimble, said that DUP ministers who refused to play a full role in the Executive would be prevented from attending intergovernmental meetings and would not have access to cabinet papers.
Mr Trimble said the Executive had discussed the matter and that the sanctions were being introduced with the aim of "ensuring good government".
He said he and the Deputy First Minister, Mr Seamus Mallon, would assume responsibility for representing the Executive on transport matters at the British-Irish Council, which comprises the Irish, British and devolved governments. They would be doing this in place of the Minister for Regional Development, Mr Peter Robinson.
In retaliation, Mr Robinson, the DUP's deputy leader, said he would order his officials not to co-operate with the First and Deputy First Ministers.
Neither Mr Robinson nor his DUP cabinet colleague, the Minister for Social Development, Mr Nigel Dodds, will be nominated to attend meetings of the Joint Ministerial Committee, which comprises representatives from the British government and the devolved administrations.
Mr Trimble pointed to statements made by the DUP that its ministers would not be bound in any way by the ministerial code of conduct, and would "uncover and reveal what is going on at the heart of government".
Mr Trimble said the Executive believed that this would be a serious breach of both ministerial and Executive confidentiality. With this in mind they would no longer be given access to cabinet papers as a matter of course.
"It's also a matter of ensuring that the administration here is not undermined by confidential material being used in a highly partisan manner, contrary to the pledge of office," he said, adding that any information given to the DUP ministers would be considered by the Executive first.
Mr Trimble rejected the suggestion that the sanctions would further hamper the effectiveness of the DUP ministers, as their tactics had already "neutered" them.
If necessary, he said, additional sanctions could be used, but he would not discuss expelling the DUP from the Executive.
"Of course, if we then find that they resign and go through this charade of temporary ministers resigning in turn, then we are going to have to consider further what has to be done to protect the integrity of the administration."
Mr Robinson described the measures as being "typical of the high-handed and panic-stricken behaviour of the First and Deputy First Minister". He said he and Mr Dodds would respond fully to the move at a press conference in Stormont today.
Mr Trimble was also questioned about allegations that the IRA murdered Mr Edward McCoy, a suspected drug dealer, last week. He said he wanted the RUC Chief Constable to make clear "his own assessment of the situation" before he would make further comment.