immobiliser fault?

It's a possibility that your fuel cut off switch has been activated. From memory, I think this is located behind a little flap in the front passenger footwell side trim - search in the area just behind the lower door hinge. Look for a little black box with a red button. If the red button has popped up like a fuse breaker, try resetting it by pressing in and see if this helps.
This solution would only be viable if the car turns over but wont start. If you are getting nothing when you turn the ignition key then the fuel cut-off won't be the issue.

Rupert
November 2019