Acually it moves forward to give access to the rear.
It's a PITA even after you've mastered it.
To gain access to the rear, do the following:
1. Lift the handle to unlock the seat back, then release the handle and push down on the top of the seat towards the front of the car until the seat locks down.
2. Push the base of the seat forward to slide the seat fully forward.
To reverse the process:
1. Do not touch the handle yet. Pull on the bottom of the front of the seat back to move the folded up seat backwards to the position it was in before (this is the seat memory).
2. Lift the handle to release the seat back, then release the handle & pull the seat back upwards until it locks.
You can avoid all this hassle and also save a few thousand pounds by buying a Panda instead 

.