Another American show with a Brit (Andrew Lincoln) in the lead. Do you not have any actors over there? (relax, I know why it happens, we're cheaper to hire!)
I'm pretty sure the actors' guild nuked that possibility. There seems to be an issue with American women loving British accents. But before you let it go to your head, I should say British-sounding, as a lot of them can't tell the difference between British, Australian, and British-esque South African accents. Sad.