OK,
Let's make things a little clearer for everyone so I don't tie myself up and lead people down the wrong path as a result of my wording or not putting in all of the information.
On the 330 Airbus has "Normal Electrics" and "Emergency Electrics", when you have neither one of these situations you are then in what would be considered as as total electrical failure. But do remember that you have battery power but it is terribly limiting.
Even in an Electrical Emergency Configuration you have the Prim 1 and Sec 1 powered and hence control, although it may be in alternate law, is still available in pitch, roll and yaw. Not to mention that on the A330 in an Electrical Emergency Configuration the A330 has Autopilot 1 available, unlike the A340, since this is a requirement for the ETOPS certification.
Now what I was referring to was the total electrical failure which means that all flight computers are not powered. This will now lead to backup. But even with backup you can still have control over the rudder as the rudder is powered by the BCM (Backup Control Module) and this provides yaw damping and direct rudder command with the pedals. The BCM computer has it own electrical generator and is supplied by the Blue or Yellow hydraulic system.
But again let us say that even this BCM failed then the horizontal plane could be controlled by asymmetric power. But to get into this situation is so unlikely. The likely hood of the Electrical Emergency Config not taking place is very unlikely as I said. But if this does not take place then there could be a moment when all 5 computers may not be powered and then Backup will become effective. In backup you have mechanical control over the horizontal stabilizer and the control over the rudder, be it electric through the BCM if it is powered. In backup you are not expected to fly the plane accurately. It is a time when you are meant to restore the flight computers. That means you need to cycle the pushbuttons. But this is only achievable if there is power to the relevant buses. If my memory serves me right even the hot battery bus will power the Prim 1.
Airbus is not perfect but they sure have a heck of a redundant system and for an aircraft to suffer a total electrical failure, ie not to even be in Electrical Emergency Config is bizarre. But even with out this Electrical Emergency Config, no battery power is hard to fathom. And the loss of a BCM which is has its own electrical generator? Nothing is impossible but the situation is highly improbable.