The Democratic Unionist Party is voting to elect a new leader, with the contest between Sir Jeffrey Donaldson and Edwin Poots on a knife edge.
Both candidates in the race to succeed Arlene Foster believe they have secured just enough support from the 36-strong electoral college of MPs and Stormont Assembly members.
The entire leadership debate has taken place in secret – with party officers having effectively silenced both men by prohibiting them from doing interviews with the media.
Tim Cairns, a former special adviser to the party, said: “In terms of speaking to the media, I think the DUP clearly missed a trick there.
“You are at your strongest whenever you are putting forward leadership platforms and the party’s in the news, the party’s in the papers, the press are interested.
“This is a time to get your agenda forward and put it forward and that’s been completely missed.”
Edwin Poots, 55, a member of the Northern Ireland Assembly for 23 years, has held several ministerial portfolios and is currently agriculture minister.
He represents the more ideological wing of the party and has courted controversy in the past with his views on evolution and sexuality.
Sir Jeffrey, an MP for 24 years, leads the party’s parliamentary team at Westminster, where he negotiated the Confidence and Supply deal with the Tories.
The 57-year-old represents the more pragmatic wing of Northern Ireland’s largest political party but this is much more than a battle between the old and new DUP.
With the DUP having witnessed three coronations, this is the first time in its 50-year history that the party has held a leadership election.
The internal revolt that ended Mrs Foster’s leadership highlighted a disconnect between the top brass and the grassroots and both candidates are promising internal reform.
The party will also elect a new deputy leader to succeed Lord Dodds, who led the party’s Westminster team when it held the balance of power there.
Paul Frew and Paula Bradley are standing alongside the long-serving East Londonderry MP Gregory Campbell.