Hi Jon - that was my thought as well, though the only info I have ever found on this is that it was written at the time the Lancashire Miners' union was being formed (1890s) - though some said 1860s or earlier-- it does seem more modern to me --

the link to the other thread has the same info as I already have -- tho my guess is since there appear to be no other recordings till Anne's and Steve's in the past couple of years (we all got the song from the same source, the Shellbacks folks on a folk music weekend, - just took me a long time to get it recorded) that the song origin info all comes from the earlier Gary & Vera Ashley recording (1970s)

Still trying to find another source -- but no luck yet