I smiled when I read it -- a charming throwback to 18th century England. JGC appears to be a Brit; my guess is that he's using this language to signal that he's not some wild-eyed radical bomb-thrower.
I think it serves a purpose very similar to "I am a member of your constituency" when writing to a congressperson in the US - basically saying "you should consider what I say because my relationship to you is _____".
