Thanks for everyone's advice.
I have previously recorded certain incidents and do have an account of everything that has happened with dates etc.
I've been scared to say too much because of what my boss said regarding how I'd lose if it was him versus me. I've been kept in my probation period as a result of this guy slandering me at every opportunity which has made it even harder for me to say anything without any protection.
As I mentioned earlier, one of the other managers backed me up and took my side on it all. As it happens this guy has just been made the manager of my department (well deserved). I've had a bit of a chat with him already and it sounds as if he's going to keep this guy out the way of our team whilst also sorting my probation out.
It isn't the world cup final win, but it's a start. As some have said themselves, I find it hard to back down and let this guy get away with what he's done. If I'm going down then you can be sure as shit he's coming with me.
Whenever anything significant happens I'll update this thread, but thanks again for all the support!