Ted Hughes wrote: Prestwich blues were singing it in about '93 when one of them died & are claiming to have started it as a non City song which then caught on during a City tour of Ireland.
That's the only one I've heard of as being claimed as definitely true, all others are a bit like this thread, what people have been told and accepted. Someone posted it somewhere on t'internet, saying he was there and a mate of whoever died.
I've always thought it was from one of our many relegations, but because someone (probably rags) were peeved that we had such a good support when we were so shite, and about to get relegated. So they were saying (or singing or printed in something), you'll have no support in whatever version of the 2nd division we were going down to.
Again that's just the version I've been told and accepted at the time.