Zetland played an important role in the protracted negotiations which led to the Government of India Act 1935, which began, subject to the implacable opposition of Winston Churchill and the "diehards" to anything that might imperil direct British rule over India, to implement those ideals.
Zetland was also an author: Rab Butler, who served as his Parliamentary Under-Secretary at the India Office, records that he asked how he could understand better his chief's thinking about the future of India and received the answer: "Read my books!"