It seems from other reviews (such as this, this and this), that this is a wonderful example of Noir writing, evoking place, menace and with a core conflict that brings loss to all those it touches.
Except I didn't really get any of that. I thought the prose was flabby, the first proper chapter starts "Dawn crept steathily", it's cliché ridden, the characters are wooden and there is no particular sense of place nor menace. The ending is pretty upbeat too. Perhaps I shouldn't have read it after Derek Raymond, even if Unsworth was a friend of his and inspired by him to write.
I finished the book but only because I was stuck in the dentist's waiting room and wanted to blot out the sound of the drilling. It didn't help much in that regard either.