Jim Wallace resigns as Lib Dem leader in the House of Lords
The former deputy first minister has been in the position since October 2013.
Former deputy first minister Jim Wallace has stepped down as Liberal Democrat leader in the House of Lords.
Once an MP and later an MSP, Lord Wallace of Tankerness said the decision to step down from his position in the Lords had not been "taken lightly".
Wallace has led the Lib Dems' 107 peers in the upper chamber since October 2013, during which time he was also deputy leader of the House as part of the Coalition Government as well as Advocate General for Scotland.
Commenting, he said: "This has been a difficult decision for me, and not one which I have taken lightly.
"After much thought I believe it is the right decision. I was first elected to the House of Commons 33 years ago. For 28 of these years, I have been on the frontline, including sixteen years in a leadership role, here in the Lords and in Scotland.
"To continue would be because of a sense of duty, but I feel that in the interests of the group, more than that is needed, particularly as we enter an important new phase in the country's political life.
"It is a huge privilege to lead such a talented and united team which, in challenging circumstances for our party, has responded so enthusiastically in articulating and campaigning for the liberal and democratic values which our country so dearly needs."
Wallace added: "I will continue to play an active part in Liberal Democrat politics, supporting the leadership of Tim Farron as we enter a period of exciting opportunity for our party."
Liberal Democrat leader Tim Farron praised Lord Wallace as "an invaluable source of political counsel".
Farron said: "Jim has been an invaluable source of political counsel. I am immensely grateful for his support and his leadership of my colleagues in the Lords.
"I look forward to continuing to work together in the months and years ahead."
Formerly MP for Orkney and Shetland, Wallace came to the Scottish Parliament to represent Orkney in 1999 and led the Scottish Liberal Democrats for 13 years between 1992 and 2005.
During the years of Labour/Liberal Democrat coalition at Holyrood, he served as deputy first minister from 1999 to 2005, and twice was acting first minister - once upon the death of the new parliament's inaugural first minister Donald Dewar in 2000, and also briefly after Henry McLeish's resignation in 2001.