Suddenly cannot open the driver side door from the inside

 

Only way of getting out is by opening and closing window / using outside door handle

 

I'm assuming a mechanical part has failed inside the door itself but would be grateful for any advice if someone has encountered this

 

Would have thought the operating cable has either come off or snapped to be honest.

Would have thought the operating cable has either come off or snapped to be honest.

 

I would go with this.  On mine the "u" crimp which hooked onto the back of the internal door handle had basically un-crimped itself and stretched out the cable.  Either get down the scrap yard and pick one one up (Octy, mk4 Golf, etc), or new from a dealer for about £25 (iirc).

 

Remove the door trim and have a look.  Tweater off, a load of torx screws around the bottom edge, and then the switch assembly and a few (2 or 3?) larger screws in the middle of the trim.  Ease out trim at the bottom and disconnect the door/puddle light.  The push door trim upwards to release from the top and disconnect LED.  If the cable is still attached to the internal handle you will know about it at this point....

Had something similar and nasty happen to me when they replaced my mirror.

I got stuck in the car as lost keys after getting into car and coat caught in the door :(

Likely a clip or cable inside the door.