DUP leader Sir Jeffrey Donaldson has for months been threatening to collapse the Stormont Executive in protest against Brexit's Northern Ireland Protocol.
However, the Lagan Valley MP has failed to follow through on his warnings - until now it seems.
After meeting with the Prime Minister last Wednesday, Sir Jeffrey said he could not guarantee that Paul Givan would remain as First Minister this week.
And after growing speculation it is now expected that Mr Givan intends to announce his resignation as First Minister later on Thursday.
Senior DUP figures are understood to be meeting to confirm the timing his resignation statement.
Why is the DUP withdrawing its First Minister?
With successive polls showing a drop in DUP support, the party is hoping a tougher stance on the Protocol will help win back unionist voters ahead of May's Assembly election.
It believes the First Minister resigning will put pressure on the UK and EU in their negotiations to agree changes to the Irish Sea trading arrangements.
The party would then seek to claim the credit for any concessions that emerge from the talks between London and Brussels.
And if no deal is secured before the election, the party is likely positioning itself to say it will not return to the Executive without changes to the Protocol.
The resignation plan also has the added benefit of distracting from the internal wrangling over the DUP's selection of Assembly candidates.
What happens if the First Minister resigns?
If Mr Givan resigns as First Minister, Sinn Féin Deputy First Minister Michelle O'Neill is automatically removed from her post due to the joint nature of their office.
A seven-day countdown then begins for both parties to re-nominate to each position.
If either party declines to re-nominate, a properly functioning Executive cannot be formed and the UK government assumes a legal responsibility to call an Assembly election within a reasonable period.
With less than 100 days until the scheduled election, it would be unlikely that Secretary of State Brandon Lewis would change the date.
While the Executive would be unable to meet, other ministers remaining in post would still be able to carry out some limited functions.
It is expected that the Stormont Assembly would still be able to meet, meaning that legislation passing through the chamber can be debated and finalised by MLAs.
By withdrawing only the First Minister, it means the DUP can appear tougher on the Protocol without fully exposing itself to criticism from rival parties if all of the Stormont institutions collapsed.
However, without a first and deputy first minister the Executive could still not make more significant decisions.
It would prevent the five-party coalition from agreeing a three-year budget, which is currently out for public consultation.
A planned official state apology by Mr Givan and Ms O'Neill to victims of historic institutional abuse, scheduled for March, may also not happen.
