The invention relates to a lock for the hinged lid, panel or bonnet of a motor vehicle. Said lock comprises a locking hook pivoted to a support by means of a pivot pin, and a keeper coacting with said hook, said hook being urged to its open or release position by a torsion spring interposed between said hook and said support, and means for locking said hook in its closing or locking position in relation to said keeper, said locking means comprising on the one hand said spring reacting against said support by means of an arm having a certain freedom of movement as far as the distance between said arm and the hook axis is concerned, and on the other hand manual control means coacting with said spring arm for varying said distance between said arm and said hook axis, whereby said spring arm will coact according to its distance from said axis with either a stop member for locking said hook in its locking or closing position, or another stop member for retaining said hook in its opening or release position.