A great subject, union songs. 'Blackleg Miner' is a good start (either Ewan MacColl or early Steeleye Span). There are just so many great labour songs though, through from good old (I dreamed I saw) Joe Hill (Check out Billy Bragg's rewritten 'I dreamed I saw Phil Ochs'), up to 'Coal not Dole' (Oysterband) via all those great Seeger and Guthrie tunes. I'll have to give this one some thought!