<p>The motor vehicle seat of the present invention includes: a seat portion (10) mounted on a pillar (7) by means of a first connecting rod assembly including a front connecting rod (11) and a rear connecting rod (9); a backrest (6) mounted on the pillar (7) by means of a second connecting rod assembly including a front connecting rod (8) and a rear connecting rod (9); a locking mechanism (21) for alternately restricting or enabling a movement of the backrest relative to the pillar, the seat being freely movable between a nominal position and a folded back position.</p>
