Actually, it was the gay pride parade that was campaigning for their own "miners" as in those underage who could go to prison if caught fancing the same sex. At 21 it was the legal age at that time where one could come out GAY. The campaign was a bit misunderstood since there were real miners on strike on the other side of UK. Together they came together to help each other.
Such fun and amazing performances. Especially, from George McKay. The movie definitely has an 80's vibe, as well as a very cool soundtrack. This movement happened right before the AIDs epidemic.