The vote to elect the next leader of the Democratic Unionist Party (DUP) will take place on 14 May, the party has said.
Party officers met on Tuesday to discuss the procedure and timetable for the election of both a new leader and deputy leader.
Agriculture Minister Edwin Poots and MP Sir Jeffrey Donaldson are bidding to succeed Arlene Foster.
She steps down as DUP leader on 28 May and first minister at the end of June.
It is the first time in the party's 50-year history that a leadership contest has taken place.
An announcement on the next leader is expected by 17:00 BST on 14 May, the party said.
The meeting, to be overseen by party chairman Lord Morrow, will be conducted virtually.
The party said contenders for both leader and deputy leader must submit their expression of interest by 17:00 BST on 6 May.
The current deputy leader of the party is Lord Dodds.
Contenders claim 'significant support'
In a statement on Tuesday evening, Lord Morrow said the date of 14 May was chosen to reflect the fact that Covid restrictions are due to be reviewed at a meeting of the NI Executive on 13 May, and that the Queen's speech will take place in Parliament on 12 May.
He said DUP representatives will be required to attend both commitments.
"In accordance with the constitution and rules of the Democratic Unionist Party, only party members, who are also members of the Northern Ireland Assembly and the House of Commons, are entitled to vote for the leader or deputy leader."
There are 28 DUP MLAs (Members of the Legislative Assembly) and eight MPs.
South Down DUP MLA Jim Wells, who lost the whip in 2018 after he criticised the party leadership in the media, told BBC News NI he had received the letter that went to all DUP MLAs and MPs on Tuesday evening, informing them about the process for the vote.
He said he was "delighted" his vote would count and reiterated he would be supporting Mr Poots.
Several senior DUP Stormont assembly members and the MP Paul Girvan have declared their support for Mr Poots.
Speaking in the Northern Ireland Assembly on Tuesday, the Lagan Valley MLA confirmed he had "no desire" to hold the position of first minister should he be elected DUP leader.
It is understood he would want to remain agriculture minister.
Sir Jeffrey, the MP for Lagan Valley, has the backing of MPs Gavin Robinson and Jim Shannon as well as Education Minister Peter Weir and Junior Minister Gordon Lyons.
Campaigners for both contenders claim their candidate has significant support within the party ranks.
Sitting in the Stormont chamber on Tuesday, Arlene Foster cut a lonely figure on the benches where she once ruled.
She was socially and politically distant from previously loyal supporters who signed a letter of no confidence in her leadership last week, forcing her to quit.
Apart for the odd polite smile to those opposite wishing her well for the future, she showed no emotion.
As she exited the chamber, one of the men who wants to replace her as leader entered through another door.
Unlike Mrs Foster, Edwin Poots shared the benches with those who have already expressed support for his leadership bid.
The contrast was stark.
In order to become party leader, a candidate must secure the support of at least 18 of the party's assembly members and MPs.
Mrs Foster announced her decision to resign after facing a revolt from DUP members last week.
She had led the party since December 2015 and was appointed first minister of Northern Ireland the following month.
BBC News NI understands that she will sever her ties with the DUP when she stands down as first minister, with sources close to her saying she thinks it is no longer the party she joined.
Mrs Foster did not take part in a Tuesday morning meeting with her assembly team.
The first minister was in the assembly chamber later as Deputy First Minister Michelle O'Neill responded to questions to the Executive Office.