Sinn Féin’s vice president Michelle O’Neill is set to face a challenge for her job.
Former Stormont education minister John O'Dowd has signalled his ambition to replace Ms 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.
Mrs O'Neill became vice president in January 2018 when her predecessor Mary Lou McDonald succeeded the retiring Gerry Adams as president.
A year earlier, Mrs 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 south of the border in May.
Sinn Féin lost two of its four MEPs and around half of its councillors.
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.”
A Sinn Féin spokesman said: “Sinn Féin is an open and democratic party.
“Any member of Sinn Féin is entitled to seek nomination for the positions elected at the party’s annual ard fheis.” - PA