^Passive agressive won't work. I'd put money on it the guy wouldn't give a fuck and call Dammit's bluff. I'd just get a chipped catflap, and lock him out (giving the other two cats the key collars). I take it James is chipped? If so just change the details to the other guy.
Have you spoke to the RSPCA? They might have some decent suggestions, and perhaps any legal issues/knowledge.
^Passive agressive won't work. I'd put money on it the guy wouldn't give a fuck and call Dammit's bluff. I'd just get a chipped catflap, and lock him out (giving the other two cats the key collars). I take it James is chipped? If so just change the details to the other guy.
Have you spoke to the RSPCA? They might have some decent suggestions, and perhaps any legal issues/knowledge.