Mike Nesbitt is to step down as leader of the Ulster Unionist Party (UUP).
Mr Nesbitt said he was stepping down to allow the UUP to select a new politician to lead it into the next elections in 2027, and signalled an intention to retire after the current Assembly term.
The Strangford MLA and health minister became UUP leader in 2024 for a second time after previous leader Doug Beattie quit following a dispute with party officers.
Mr Nesbitt, a former broadcast journalist, had previously been party leader between between 2012 and 2017 but quit following a difficult Assembly election result.
He is the first person to lead the party twice.
The next Northern Ireland Assembly elections must be held by May 2027.
In a statement, Mr Nesbitt said: "The next five-year mandate stretches to May 2032, the month I hope to celebrate my 75th birthday.
"That's a commitment to full-time politics I just do not feel I can make.
"And I would not be comfortably seeking a vote knowing that privately I was intending to retire during the mandate."
He added: "I retook the leadership to do a short-term job of getting the party match-fit for the forthcoming election campaign.
"That job is now done so the time is right to select the politician who will lead us into the May 2027 polls promoting our brand of confident, responsible unionism."
The UUP said it would outline the process for leadership selection "ensuring an inclusive, engaging and seamless transition".
Party chairman Tom Elliott said: "We are deeply grateful to Mike for his decades of service and unwavering dedication to improving our society."
