Though born in Ilford, he was brought up in the Belle Vue area of Bradford, Yorkshire,[1] where he attended primary and secondary school.

[1] At the general election in 1945 he stood unsuccessfully at the Pembrokeshire constituency in Wales, losing by only 168 votes to the Liberal Party candidate Gwilym Lloyd George.

Percy Lucas, a friend and fellow MP, mentioned in his memoir Five Up that Fienburgh also had a burgeoning media career with both Granada Television and the Sunday Express.

Fienburgh wrote several books, including non-fiction works such as Steel is Power – The Case for Nationalisation and 25 Momentous Years: A 25th Anniversary in the History of the Daily Herald.

However, his best remembered book is a posthumously published novel, No Love For Johnnie, a cynical portrayal of British politics in the late 1950s that was later adapted as a film starring Peter Finch.

One near-contemporary critic, Alan Lovell, writing in the New Left Review in 1961, considered No Love For Johnnie a "bad novel" and wrote that "Fienburgh seems to have had no conception of what idealism means".

Geoffrey Wheatcroft in The Observer in 2001 suggested that No Love for Johnnie was the archetype of a genre that he named "the Labour Party novel of disillusionment".