Vauxhall ADAM seats not folding back after being folded forward

Two seater car, when folding the seats forward for someone to go into the back seat, we've always struggled to get the seat to go back to a regular position. However, recently the seat literally wouldn't go back again. Had to have my husband literally jam it back into a driving position. Now, don't want to put anything or anyone in the back seat for fear of the seat being permanently jammed in the forward position.