King was a member of Dave Barrett's 1972 BC NDP provincial government, serving in the post of Minister of Labour.

He entered politics as a teenager in 1943, when he acted as a runner between polling stations and the campaign headquarters of Herbert Herridge, CCF MLA for Rossland-Trail.

After moving to Revelstoke in 1952, he became an organizer for the CCF at the constituency level and worked on Vincent Segur's campaign in the 1952 provincial election.

In 1960 King served as campaign manager for George Hobbs, who won the Revelstoke-Slocan seat for the CCF.

King served as Leader of the Opposition[5] until Barrett returned to the House upon winning a by-election in June 1976.