I'll check out exactly what Christy Moore says about this in his book tonight, but as far as I remember the song was given to him on a visit to Derry and he was told it was written by Bobby Sands. There's another song that Christy also sings called McIlhatton which is also attributed to Sands, but I think initially it was written under a pen name.

The song was written in the H-Blocks and to my memory it started to be sung only around the time of the huger strikes. Bobby Sands died in 1981 and could easily have heard Lightfoot's song, which was popular here either before or after he was imprisoned.

Someone more expert than me on the history of the H-Blocks protest might be able to comment on whether Bobby Sands would have had access to Radio in the prison at any stage. Towards the end all priveleges had been taken away, but this may not have been the case in the early part of his sentence.

I think it is almost certain that the song was written to the air of Lightfoot's song rather than the other way round.