The Ulster Unionist Party is to withdraw its three ministers from the Executive if it fails to win the necessary support for an Assembly motion to exclude Sinn FΘin from government.
The move was announced by the UUP leader, Mr David Trimble, on Saturday following a lengthy meeting by party officers in the wake of the latest 24-hour suspension of the institutions.
The party will table the exclusion motion in the Assembly today but it will take up to three weeks for it to come before the chamber for a vote. In the absence of cross-community support, the motion is expected to fail, in which case the three UUP ministers, Sir Reg Empey, Mr Michael McGimpsey and Mr Sam Foster, will leave office, Mr Trimble announced.
The UUP leader said it was time for his party to "bring matters to a head". Another one-day suspension followed by another six weeks of limbo would simply not resolve the current impasse, he told the BBC's Inside Politics programme.
"Simply to put off, simply to give six weeks more for what, hoping something will happen, is not credible and indeed in the present situation, I think it is positively harmful because there is a rising tide of anger in the community in Northern Ireland.
"When I resigned originally it was for the purpose of bringing matters to a head. I think I was vindicated by what happened subsequently. There was an impetus which I don't want to see disappear. Therefore, I am taking further action to ensure that people keep their minds concentrated on what must happen."
While stressing that he would not rule out the possibility of getting the necessary cross-community support for the motion, Mr Trimble said in the case of its being defeated it would be "utterly hypocritical" for his party's ministers to remain in office.
"We are not like those parties who are hypocritical in this respect and we would follow through. People need to be cognisant of the fact that we have travelled hopefully over the past three years, supported an inclusive system, given republicans the opportunity to participate.
" In fact, I have taken quite significant risks personally to give people that opportunity, but it was on the basis that they carry out their obligations under the Agreement.
"They haven't done that and sooner or later we have to say: 'That's it. A line has to be drawn.' I have held my hand on this . . . But there is an inevitable consequence to an absence of republican decommissioning
"It would be impossible for UUP ministers to continue participating in government with Sinn FΘin, we couldn't do so with credibility, we will not do so."
The withdrawal could be prevented only by a definite move by the IRA on a weapons handover.
"The promise was made that they would put weapons beyond use. There is a procedure, there is a decommissioning commission, there is legislation, there is a decommissioning scheme.
"What we are saying to people is that they must begin a credible process of decommissioning. If that happens, then obviously we will take account of that."
Mr Trimble rejected accusations that he was putting his party's interest before that of peace.