Richard Leonard has resigned from his post as Scottish Labour leader.
The Central Scotland MSP had been in charge of the party for three years, beating Anas Sarwar in the race to replace Kezia Dugdale.
Mr Leonard said speculation over his position had “become a distraction” and that stepping down was “in the best interests of the party”.
The move comes just four months before the next Scottish Parliament election – and after Mr Leonard faced damaging calls from leading MSPs within the party to go.
Last September, Mr Leonard insisted he would lead Scottish Labour into May’s election, despite party MSPs James Kelly, Daniel Johnson and Jenny Marra all speaking out publicly against him.
The latest from our Scottish parliament poll tracker – constituency voting intentions:
More out later this eve. pic.twitter.com/h4btD16BpN
— Britain Elects (@BritainElects) January 14, 2021
In a statement, Mr Leonard said: “I have thought long and hard over the Christmas period about what this crisis means, and the approach Scottish Labour takes to help tackle it.
“I have also considered what the speculation about my leadership does to our ability to get Labour’s message across. This has become a distraction.
“I have come to the conclusion it is in the best interests of the party that I step aside as leader of Scottish Labour with immediate effect.
“This was not an easy decision, but after three years I feel it is the right one for me and for the Party.”
The 57-year-old added: “I retain my faith in the Labour Party as the party that offers hope to people and that remains the only vehicle for the realisation of that hope.
“Whilst I step down from the leadership today, the work goes on, and I will play my constructive part as an MSP in winning support for Labour’s vision of a better future in a democratic economy and a socialist society.”
Sir Keir Starmer said Richard Leonard should be “very proud” of his achievements as Scottish Labour leader.
The Labour leader said: “I would like to thank Richard for his service to our party and his unwavering commitment to the values he believes in.
“Richard has led Scottish Labour through one of the most challenging and difficult periods in our country’s history, including a general election and the pandemic.
“Even from opposition, he has achieved a considerable amount for which he should be very proud.
“This includes securing a commitment for the creation of a national care service, securing action on a Jobs Guarantee Scheme to deal with youth unemployment, securing a human rights-based public inquiry into the treatment of care home residents during the Covid pandemic and securing support for a Fair Rents Bill to give new rights to tenants.
“He has done so with dedication to the values of our movement.
“I wish Richard the very best for the future as one of our MSPs and know that he will continue to play an important role in Scottish Labour.”
Scotland’s First Minister Nicola Sturgeon said: “Despite our political differences, I’ve always liked Richard Leonard.
“He is a decent guy and I wish him well for the future.”
Despite our political differences, I’ve always liked Richard Leonard. He is a decent guy and I wish him well for the future.
— Nicola Sturgeon (@NicolaSturgeon) January 14, 2021
Scottish Conservative MSP Ruth Davidson tweeted: “When I stepped down in August 2019, I discovered that political resignations are odd things, like reading obituaries when you are still alive.
“Whatever else is written about Richard, I have to say I always found him a thoroughly decent man and a committed campaigner.”
Scottish Lib Dems leader Willie Rennie tweeted: “Richard Leonard is a good man who cares deeply about his politics and his party. There is no better evidence of that than his decision to step down from the top job.”
Scottish Labour MSP Neil Findlay, meanwhile, hit out at some of his party colleagues on Twitter.
He wrote: “Looks like those who have led a 3 year campaign of briefings to journalists, leaks of private conversations and the constant feeding of stories to the media to bring down a decent and honest man have succeeded.
“These flinching cowards and sneering traitors make me sick.”