Gerry Adams is set to indicate when he plans to retire during the Sinn Fein annual conference.
The republic veteran and party president will deliver a speech billed "historic and significant" in Dublin on Saturday evening.
Mr Adams, 69, is expected to provide details about the ongoing process of a leadership transition.
His plan, formulated along with the late Martin McGuinness, has already seen Michelle O'Neill take the role of Sinn Fein leader at Stormont - the Northern Ireland Assembly.
Mary Lou McDonald, the current deputy leader of the Sinn Fein party, is widely touted to replace Mr Adams.
Mr Adams has been the party president since 1983.
He goes before the Ard Fheis (annual conference) each year to seek re-election and that formality is expected to be repeated on Saturday.
However he is also expected to indicate how long he intends to hold on to the reins of power.
The long-standing MP for west Belfast switched his focus to the Dublin parliament in 2011, becoming a TD for Co Louth.
Sinn Fein has made steady gains in the Irish Republic in recent polls but many believe the prospects of further growth is limited due to the presence of Troubles era figures.
The conference will be the first since Mr McGuinness, a former IRA commander, died in March.