Rear passenger seat stuck down, seat belt also tight

Hi,

As we do most days we put the rear passenger seat down to let our little ones into the boot seats, went to pull up the rear seat up and it feels jammed, as does the seat belt (Not sure if connected). I've tried to take the back cover of the seat off and found the cable which links to the release catch and can see and feel it moving and it does seem to unlatch, but the seat belt is stuck as well.

As the seat belt is stuck can this cause the seat to stay locked down?? The bobble bit on...

Rear passenger seat stuck down, seat belt also tight