Sinn Féin's vice president is set to face a challenge for her job.
Former Stormont education minister John O'Dowd has signalled his ambition to replace Michelle O'Neill in the senior leadership role.
Mr O'Dowd is hoping to secure nominations from party colleagues ahead of a potential challenge at November's Sinn Féin Ard Fheis.
Ms O'Neill became vice president in January 2018 when her predecessor Mary Lou McDonald succeeded the retiring Gerry Adams as president.
A year earlier, Ms O'Neill was appointed the party's Stormont leader after the late Martin McGuinness stood down on health grounds.
The move from Mr O'Dowd comes in the wake of the party's poor performance in the European and local council elections in May.
Sinn Féin lost two of its four MEPs and around half of its councillors.
I can confirm I will be seeking nominations for Leas Uachtarán of Sinn Féin as we approach the Ard Fheis and the annual election of party leadership. I look forward to the debate across the party and island.— John O' Dowd (@JohnODowdSF) August 31, 2019
Mr O'Dowd confirmed his intention to the Belfast Telegraph.
"I can confirm that I am going forward and right now I am speaking to fellow party members to secure nominations," he said.
"I would prefer to talk to more party members first but I will release a more detailed statement at a later date."
In a statement, Ms O'Neill says that she will seek re-election as the party's vice-president at the Ard Fheis in November.
"Sinn Féin is a democratic party and I welcome democratic debate and choice within the party," she said.
"I will ask the party membership to endorse my record by re-electing me to the position of Leas Uachtarán of the party."