Peugeot 206 2005 sport 3-door. The driver's seat folded forward to let passengers in and has jammed in the forward position I've been able to push the seat back and lock it enough to drive it (painful) now it's sat on the drive with the front seat out and meet cussing at it as I can't see a problem in the mechanism.
Can't free up the seat to even sit up and in normal driving position.

Smiffy, May 2022

"Right lay on seat in the fully reclined postion and push the levers back with a bit of force . You should hear it click then whilst still lying on it push levers forward quickly this worked for me try a few times if doesn't work as the mechanism is jammed and it needs to be un jammed force helps some times !!! £650 for a new seat my arse!!! Annoying problem granted hope this helps !!

Mike
August 2010"

From this page:
https://www.howtomendit.com/answers.php?id=171210

Lots more solutions on that page (as well as a lot of adverse comments about Peugeot)

3rjbf, May 2022