Born as Clifford Groocock Hincks, he was brought up as a Methodist, and from 1917 was a lay preacher.
[3] He became active in the Hinckley and District Hosiery Union, and in 1930 he was elected as its general secretary.
[2] Under Groocock's leadership, the Hinckley union grew, with membership reaching 6,000 by 1939.
Despite the title, this post was only that of second-in-command, with Moulden as general president being its most prominent figure.
Like Moulden, Groocock saw himself as a social democrat, favouring good relationships with employers and minimising industrial action.