Former health minister Susan Deacon is to stand down from the Scottish Parliament at the next election.
Susan Deacon MSP was the first health minister under devolution
The Edinburgh East and Musselburgh MSP said she felt it was time to move on and find new challenges.
Ms Deacon was the first health minister under devolution but moved to the backbenches in 2001.
She announced she would not be seeking re-election at a meeting of East Edinburgh Labour Party members on Sunday.
The politician revealed her decision some nine months before next year's Holyrood and council elections to enable the local party to select a new candidate.
She said she took the step after "a great deal of reflection".
In a statement to party members Ms Deacon said: "By the time of the election, I will have been MSP for Edinburgh East and Musselburgh for eight years.
"Throughout this time I have worked hard to be an effective and active constituency representative and to contribute positively to the work of the parliament and the executive.
"I have also endeavoured to make an impact on wider issues and to work with others to promote progressive change.
"I now feel it is time for me to move on, to seek new challenges and to channel my energies in other ways."
The MSP, who lives in Musselburgh with her partner John Boothman and their two children, has been the area's MSP since the creation of the parliament.
She served as health minister from 1999 to 2001 and is currently a member of the Enterprise and Culture Committee and the Audit Committee.
Prior to being elected, Ms Deacon worked at senior level in local government, management consultancy and in higher education.