I agree with Gibb Sahib that it doesn't feel like a traditional song, but has a more arty feel to it. I'm not going to go into "what is a folk song" as that debate could lead us into ever-decreasing circles, and we know where that leads. However, there are other issues that point to it not being traditional:

1. there don't appear to be multiple collected copies and different versions, apart from what recent folk revival singers may have done.

2. It doesn't show up in older song collections and so far as I know, it was not sung before the 1970s.

3. And this is a clincher - Steve Roud has made the judgement not to include it in his fabulous index.

All that aside, it is still a very good song and I shall continue to sing it.

Tradsinger