He was educated first at William Hulme's Grammar School, then studied medicine at Owens College, Manchester and the London Hospital.

[2][3] He unsuccessfully contested Wycombe in the 1931 election, but succeeded in Islington North at the 1937 by-election where he remained an MP until 1950 upon his elevation to the peerage.

Haden-Guest founded the Labour Party Commonwealth Group, and was a member of the Anderson Committee whose work led to the development of the Government's Evacuation Scheme during summer 1938.

During the Second World War Haden-Guest contributed to a social survey published by the Fabian Society regarding evacuation.

[10] Bertrand Russell described Haden-Guest as "a theosophist with a fiery temper and a considerable libido" and "very anti-Bolshevik".