Former Scottish Labour leader Johann Lamont has backed Kezia Dugdale to take over at the helm of the party.
Ms Lamont said the current deputy could give Labour “a strong and modern voice” in the new Scotland.
Her endorsement came as MSP Ken Macintosh formally launched his leadership bid.
Mr Macintosh was runner-up to Ms Lamont in 2011 when she took over from Iain Gray in the wake of the party’s Scottish election loss.
Ms Lamont quit in 2014 after the independence referendum, with Jim Murphy taking over for just eight months before resigning after Labour’s general election defeat.
Writing on the Labour Hame website, she said the job “cannot be a zero-hours contract” for the new leader but a “long-term, long-haul appointment”.
She said: “Scottish Labour is still in shock and we have many questions to ask of ourselves, arguments to reflect on and changes to make. That will not be done quickly and cannot be for elected politicians alone.
“Electing a new leader will not be enough but the right leader, supported and encouraged, can guide and drive that change.
“It is hardly the easiest of jobs. Indeed, I have reflected that too often our party comes together to elect a leader and then steps back, arms folded, waiting to be disappointed.
“We cannot allow that luxury now. Choosing a leader must be for the long-term. There is no quick fix, no gimmick, no short-term ploy that will match the respect we need to show those who have turned away.”
Ms Lamont, who backed former Labour MP Katy Clark in the deputy contest last year over eventual winner Ms Dugdale, said she now believes the MSP is the “woman to lead the change” in Labour.
The former leader said Ms Dugdale is “part of the post-referendum generation, shaped by that debate but not scarred by the arguments of the pre-Scottish Parliament generation – hers is the generation charged with healing divisions and responding to a changed Scotland”.
“Her instinct is to co-operate and that is good. Her politics are grounded in making a difference and tackling inequality, and that means she can be a powerful voice for action over rhetoric,” Ms Lamont said.
“She can give Labour a strong voice, a modern voice, in our new Scotland.”