Prior to the 2003 election he was moved from first to fifth place on the Conservative's list for Mid Scotland and Fife.
After parliament was dissolved he defected to the newly formed Scottish People's Alliance.
[2] He subsequently fought Stirling for the SPA but came in a poor sixth place with only 642 votes (2.2%).
Harding was a member of the national policy committee of the New Party, the successor to the SPA.
[3] Keith Harding died in Redon, Ille-et-Vilaine, France on 15 November 2021, at the age of 82.