Edwin Poots will turn down the first minister's role at Stormont if he is elected DUP leader.
The Lagan Valley MLA, the firm favourite to succeed Arlene Foster, already has a plan for his first 90 days as party leader.
He sees the party leadership role as more important than being first minister alongside Sinn Fein's deputy First Minister Michelle O'Neill.
In an exclusive statement to Sunday Life, a spokesman for Mr Poots confirmed he would not be first minister, saying: "Edwin will split the roles of leader of the party and first minister."
The spokesman revealed Mr Poots, currently the agriculture minister, has a plan for his first 90 days which involves "rebuilding the core and the foundation of the party".
The Stormont minister's aim is to re-energise the party membership and electorate.
He wants to secure reach out to the "broadest community to ensure the continued success of the Union for all our people".
The spokesman said: "Edwin knows the job at hand and for that reason will split the roles of leader of the party and first minister. (He will) reshape the party for the future whilst putting in place a good team to work with him and the other parties in a five-party Executive, ensuring that people of Northern Ireland get the government they need.
"The policies of promoting the NHS and building our economy are central to the benefit of being part of the Union for all our people, no matter class, creed or gender. Together, we can make this work."
Mr Poots would consult with party colleagues over who would take on the first minister role in the Executive.
His only potential challenger is Lagan Valley MP Sir Jeffrey Donaldson, who has yet to declare his candidacy. He is due to make an announcement in the coming days, with insiders saying he is likely to run.
Among Sir Jeffrey's key supporters are Economy Minister Diane Dodds, her husband and former North Belfast MP Lord Dodds and East Belfast MP Gavin Robinson.
Antrim and Newtownabbey councillor Philip Brett is understood to have been tasked to work on any Donaldson campaign.
The DUP leadership battle will be decided by its 35 MPs and MLAs, the majority of whom seem to be siding with Mr Poots.
Sources in his camp remain hopeful Sir Jeffrey could withdraw after spending the weekend sounding out politicians.
Five MLAs and one MP have already publicly pledged their support to Mr Poots, including South Belfast Assemblyman Christopher Stalford, who was close to outgoing DUP leader Mrs Foster and would have been viewed as a natural Donaldson backer.
Video endorsements from each shared on social media are being seen as a muscle-flexing tactic to force Sir Jeffrey into reconsidering a leadership challenge.
A DUP source said: "Jeffrey won't involve himself in a leadership contest he knows he is going to lose. The reason why he has delayed announcing his candidacy is because he is sounding out whether he has the support of the majority of the 35 MLAs and MPs. There is a fair chance come Monday that he might confirm that he is not going to take part."
Some Poots supporters are portraying Sir Jeffrey as 'Arlene Foster Mk. II', pointing to how they are both from an Ulster Unionist background and share the same political outlook.
Referencing the lyrics from The Who rock classic Won't Get Fooled Again, another supporter of Mr Poots said: "If Jeffrey were to become leader it would be a case of, 'meet the new boss, same as the old boss'.
"There needs to be real change ahead of next year's Assembly elections or Stormont will come back with a Sinn Fein first minister."
A Lucid Talk opinion poll in February saw DUP support plunge to a 20-year low from 28 per cent to 19pc, with most of the missing vote going to Jim Allister's hardline TUV, which increased its share to 10pc. Sinn Fein were on 24pc.
The prospect of carnage at next year's Assembly elections hastened the internal coup against Mrs Foster and the DUP's move further to the right.
Her position was further weakened when she was one of only five DUP MLAs who abstained on a Stormont motion calling for a ban on gay 'conversion therapy'.
Should Mr Poots become the next party leader, an early major test will be his response to an Irish language act - a key Sinn Fein demand.
DUP hardliners want him to oppose the legislation at all costs - a move that could result in Sinn Fein collapsing the Assembly and forcing an election.
But Sinn Fein insiders have briefed journalists that Mr Poots helped negotiate the substance and detail of the Irish language legislation in the first 2017 negotiation and "not one iota has changed in the draft bill".
The Sinn Fein source added: "While some commentators argue this may be a wedge between him and Sinn Fein, it may not be. But you can't discount the possibility of him moving to oppose it (Irish language act)."
In a video shared on social media yesterday morning, Mr Poots revealed his leadership campaign manager, North Antrim MLA Paul Frew, had informed him he has a winning majority.
Mr Poots said: "I've been speaking to my campaign manager this morning, and it was great to hear the news that he has confirmed that the majority of the electoral college is behind my bid for the DUP leadership. That's something we are going to build upon over the course of the next week."
Mr Frew added: "I am delighted to confirm Edwin has received endorsements from a majority of the electoral college including MLAs and MPs.
"As campaign manager, I take nothing for granted and am very grateful for the support Edwin has received from colleagues."
Declarations of an early victory from Mr Poots are being downplayed by those close to his likely DUP leadership rival Mr Donaldson.
The latter's camp claims to have the backing of several MPs and MLAs, with one source saying: "He has very strong support from the parliamentary team and has more firm commitments from MLAs than Mr Poots."
Among those MLAs are the five not to lend their names to an internal DUP letter calling for Arlene Foster to quit as leader. They are Mrs Foster herself, Education Minister Peter Weir, Economy Minister Diane Dodds, Gordon Lyons and Pam Cameron. Several powerful DUP backroom figures have also endorsed Mr Donaldson's campaign.