Kezia Dugdale has stepped down as Scottish Labour leader with immediate effect.
The Aberdeen politician, who took on the leadership role in August 2015, said she was leaving the party in a better position than she found it.
Dugdale said the party needs a candidate who can bring "fresh energy, drive and a new mandate" to the party, and added that her successor needs "space and time" to prepare for the next Scottish Parliament election in 2021.
"I have thought long and hard about this. I care deeply about the Labour Party - I love it and I have devoted my adult life to serving it in a number of different capacities," Dugdale told the BBC.
"And I have just come to the conclusion that the best thing for it, the Labour Party, this precious, precious thing that has done so much good in our country, and indeed for me, is to pass that baton on."
Dugdale backed Labour MP Owen Smith in his leadership challenge against Jeremy Corbyn last year.