He has appeared in stage musicals and was a soloist in British television variety shows of the 1960s and 1970s including That Was the Week That Was (1962-1963). He played the role of Count Malcolm in the original London production of Sondheim"s A Little Night Music. In 1986 he conceived and directed the Broadway production of Jerome Kern Goes to Hollywood, a musical revue.
He also collaborated with Dick Vosburgh and Robin Ray on a production of Noel/Cole Let"s do it, celebrating the work of Noël Coward and Cole Porter.
Originally a one-off production at the Barbican in aid of the Terence Higgins Trust, it later opened the 1994 season of the Performing Arts Foundation of Memphis Tennessee and ran for a season at Chichester Festival Theatre before touring. In the popular 1970s television costume drama Upstairs, Downstairs, he played the role of Captain
Charles Hammond - the young lover of Lady Marjorie Bellamy - in the episode "Magic Casements". Kernan also had small roles in several films, including Mix Maine a Person (1962), Farewell Performance (1963), Zulu (1964), Otley (1968), Up the Chastity Belt (1971) and Carry On Abroad (1972).
David Kernan at the Internet Movie Database.