Born in Glasgow, Hinshelwood became a fitter at an ironworks, and joined the Social Democratic Federation (SDF) and the Amalgamated Society of Engineers (ASE).
By the 1918 UK general election, the BSP had affiliated to the Labour Party, and Hinshelwood was selected to contest Portsmouth Central.
[1][4][5] The BSP became a founding element of the Communist Party of Great Britain (CPGB), for which Hinshelwood was elected to Greenock Town Council.
[6] On release, Hinshelwood remained active in the CPGB, but devoted more time to the Amalgamated Engineering Union, successor of the ASE.
He represented it at the 1930 Trades Union Congress, at which he spoke in support of unemployed workers who had formed an unofficial delegation, but was soon excluded from the event for interrupting speakers.