Stewie on Family Guy

Is the accent used by Stewie (the baby) on "Family Guy" upper-RP?

What about the accent used by the butler (Jeffrey) on "Fresh Prince of Bel-Air"? It kind of sounds like he is trying to imitate upper-RP. He seems to be doing a pretty decent job of it too but the fact that he IS trying is somewhat apparent.

What about the voice of Jeremy Irons when he is hosting the Mozart programme on WQXR (96.3 FM New York) on Fridays from 9 to 11 PM? To me it sounds like ultra-conservative, 18th century upper-RP. He also has a very particular voice quality which the other two characters lack.

Comments?

Stewie has a comical, exaggerated version of Upper-RP, just one of many ridiculous things about that character.

The actor who played Geoffrey on "Fresh Prince" was actually British. He sounded like he had a fairly typical drama school-trained accent, which always sounds a little forced to me no matter what.

I would attribute the odd quality of Jeremy Irons' accent perhaps to the fact that he has lived in Ireland for many years. Although, he also was trained at drama school at a time when RP was rigidly enforced, so I'm not sure.