During World War II he served on Sydney City Council's National Emergency Services committee from 1942 to 1945, advocating the construction of underground air-raid shelters and other measures preparing for possible attack. His son, Private David Bruce Harding (who attended Sydney Church of England Grammar School, 1930-1935) of &lt;a href="2/17th%20Battalion%20%28Australia%29"&gt;2/17th Battalion&lt;/a&gt; died on active service in the Salamaua–Lae campaign on 10 October 1943. At the May 1944 state election Harding stood as the Democratic Party candidate for the seat of North Sydney but was unsuccessful against Labor's James Geraghty.