Originally Posted by CPW

I don't think that's quite right. A right of abode certificate will not be issued to someone who has a valid British citizen passport. However, person with a right of abode certificate in another valid passport could apply for a British passport; the passport issuing authority might insist on cancelling the right of abode certificate (but then again it might not insist on doing that), but it wouldn't deny a British passport to someone who was entitled to one simply because the person already had a right of abode certificate.