DUP could collapse Northern Ireland Assembly on Monday
The future of the Executive will hinge on a speech delivered by Theresa Villiers in the House of Commons on Monday.
If she does not move to suspend the Assembly or to punish Sinn Fein in some way then the DUP will take action itself.
Last night the party was remaining tight-lipped - it has the weekend to consider it - but it is understood the DUP told Ms Villiers it could involve withdrawal from the Assembly. That would cause it to collapse.
Other options are not attending Assembly events or the Executive itself. When the DUP unsuccessfully proposed a motion to adjourn the Assembly it specified that there could be emergency meetings.
The party intends carefully studying the Secretary of State's speech to decide what action is needed.
International pressure is growing for talks to be held and to resolve the situation. They will be chaired by Ms Villiers but Charlie Flanagan, the Irish Foreign Minister, will also be present for sessions which affect the Republic and its relations with the UK.
Last night Senator Gary Hart, the US Special Envoy to Northern Ireland, leant the US's weight to the venture.
He said: "The United States welcomes the announcement by UK Prime Minister Cameron and Irish Taoiseach Kenny that the governments will convene urgent talks next week with the parties that subscribed to the Stormont House Agreement."
He added: "In recent conversations with Northern Ireland party leaders and the UK and Irish governments, I strongly encouraged all stakeholders to come back together for intensive talks - to build trust, address remnant paramilitary activity and resume implementation of the Stormont House Agreement."
The Stormont House Agreement, concluded last Christmas, was never implemented because Sinn Fein concerns over Westminister welfare cuts.