The seatbelt clip was wedged in the driver's door (when shut) so that it wouldn't open from the inside or the outside - neither door release handle was engaging with the lock mechanism. I've managed to release the seatbelt clip and open the door using the inside handle (which is working again) but the outside handle is still not not engaging with the lock mechanism. It lifts all the way but there's no click, and you can't see the door catch move slightly like it does on the passenger side. Turning the key in the lock is having no effect. The central locking is working fine from the plipper and from the dashboard.
At one point I was able to lift the handle and turn the key twice round clockwise but it didn't change anything. I can't reverse this.
Am I looking at a part replacement job or is there a simple way of resetting the locking mechanism to see if it's some temporary electronic glitch?