[Ray-of-Sunshine]

Don't have my owners manual to hand but if the boot power close has not worked correctly there is a procedure in the book to manually close the boot to do with trying the boot handle and having both doors open and switching the ignition on and off to get the power close working again.

 

[Ray-of-Sunshine]

SOLUTION: Borrowed my nephew (kid small enough to climb through the pass-through) and he pulled the emergency release. Thanks for the advice here!

Where is the emergency trunk release, just in case anybody else needs to know?

Is it accessible without removing the inside plastic trim cover?

Actually the solution is far simpler than that, if you want to pull the emergency boot/trunk release all you need to do is remove the pass-though panel in the back seat and pull the large red ring you will see at the bottom of the pass through!