 After working several years as a Solicitor, Robson stood for, and was elected to, parliament on 29 August 1936 at a by-election for the seat of Vaucluse.He served many years on the backbenches, he enlisted in the Second World War and served with distinction during the war, gaining promotion to lieutenant colonel and receiving the Distinguished Service Order for his service.Returning to politics, he had missed the foundation of the Liberal Party in 1945.