Democratic Unionist Party leadership contenders Jeffrey Donaldson and Edwin Poots have issued eve-of-poll messages in a final bid to clinch the position.
The pair are running to replace outgoing leader Arlene Foster who announced her resignation last month.
It is the first leadership contest in the DUP’s 50-year history.
Mr Donaldson and Mr Poots face several challenges, including post-Brexit trading arrangements under the Northern Ireland Protocol, which has been reviled by unionists and loyalists as a “border in the Irish Sea”.
They will also want to unite unionism which is in such turmoil that the leader of the second largest pro-union party, the UUP, has also stepped down.
Just one candidate, former army captain Doug Beattie, has indicated he will run to replace outgoing leader Steve Aiken.
Under a “strength and experience to lead” strapline, Mr Poots, the current Stormont Agriculture minister, tells the party electorate that he believes he has the “right plan to reform our party” and to “reinvigorate unionism”.
Mr Poots previously indicated he will nominate a colleague to serve as first minister.
Mr Donaldson’s final message to voters includes a pledge to stand in the next Assembly election, scheduled to take place in May 2021, and become first minister.
He has promised “major changes” and “greater participative structures” within the party, and pledged to provide “united leadership to unionism and the country”.
The DUP’s 28 MLAs and eight MPs will meet virtually on Friday to hear both men’s pitches before voting in a secret ballot.
Mr Donaldson and Mr Poots will have 10 minutes each to speak to the electoral college.
The contenders to succeed Nigel Dodds as deputy leader, Gregory Campbell, Paula Bradley and Paul Frew, will each have five minutes to make their case.
Voters will cast their ballot at party headquarters on Friday afternoon before polls are due to close at 4pm.
Mrs Foster confirmed on Wednesday that she would be voting, but declined to say who she would be backing.
She resigned following an internal revolt against her leadership.
The move came in the form of a letter of no confidence signed by a majority of the party’s senior elected representatives.
The outgoing DUP leader will step down from that role on May 28, and as Stormont First Minister at the end of June.
Earlier Sinn Féin president Mary Lou McDonald warned the DUP against any move that could destabilise powersharing in Northern Ireland.
She said the leadership of the party is “entirely a matter for themselves”, but she added: “Powersharing has to work for everyone.”
“It is very, very unwise in the mouth of a leadership election for anyone in political unionism to be talking about destabilising the institutions,” she said.
“The institutions have to work, powersharing has to work, the Good Friday Agreement has to work, Stormont House (Agreement) needs to be delivered, Acht na Gaeilge (Irish language act) and the cultural legislative package needs to be delivered.
“And the reason why all these things need to happen is because that’s how we give each of our citizens the best chance, the best shot at having a decent quality of life and living in a stable, respectful society.”