 On 27 October 1939, a month after the outbreak of the Second World War, Tuker was promoted to full colonel (with seniority from 1 July 1936).He became Director of Military Training in India in 1940.A temporary brigadier by this time, he was appointed General Officer Commanding (GOC) 34th Indian Infantry Division on 1 October 1941 with the acting rank of major-general.