Harold Davy was the President of the Hull 2nd Branch of the Amalgamated Society of Woodworkers (today part of UCATT) and, as such, a mass leader Humberside building workers during the 1920s and 1930s.
A contributor to the rank and file journal, New Builders' Leader, he held office as an executive member of both the Hull Trades Council and the City Labour Party but was expelled for being a Communist Party member.
A shop steward on major jobs on both on the Tyne and Humber, he led a number of militant struggles. On the latter, he successfully led a demand for better overtime rates of pay, and succeeded in obtaining half day up till 6.30 pm, with double time for Sunday. In both cases, the victory was done without official assistance.