[1][2][3][4][5][6] In July 1915, Duncan-Hughes left Australia for England with the intention of serving in World War I and was commissioned as a lieutenant in the Royal Field Artillery of the British Army in September 1915.

This led the more dominant Liberal Union to oppose all federal Nationalist MPs who were members of the state National Party at the 1922 election.

[12][13][14] Duncan-Hughes and his colleague Malcolm Cameron were invited to participate in the first post-election meeting of the Nationalist caucus on 17 January 1923.

[15] In reference to the position of Prime Minister Billy Hughes, he reportedly "explained that he would support the Nationalist party, but he held no reservations on the question of leadership".

[18][19] During his political career, he also served as the president of the Adelaide Club from 1935 to 1937 and was a board member of the Wyatt Benevolent Institution.