PROBLEM: Drivers door can not be opened from the outside. It can be opened from the inside. The drivers side door key operates central locking normally EXCEPT the driver's door.
CAUSE: The car had been left in winter conditions for 3 weeks and the electric motor inside the central locking unit had seized. Evidence of rusty water (probably condensation) around the motor.
SOLUTION : Gain access to the central locking unit and free the motor.
PROCEDURE : If you can get the remote unit out of the door, you have done the hard part. Remove the electrical connector then split the unit by removing a couple of screws and that's it. Wrap a piece of soft fabric around the exposed gear and just twist it until it frees up.