The petitioner is the plaintiff. The petitioner filed the suit for partition of the suit property against his son. The petitioner filed amendment petition as well as petition under Order I Rule 10 C.P.C. for impleading the purchasers of the land from his son during the pendency of the suit. The amendment petition is that the lands sold by the defendant, in excess of his share, in favour of the purchasers be declared as illegal and void. The amendment is allowed but the prayer of the petitioner for impleading the purchasers as defendants in the case has been rejected. It is submitted that the purchasers are necessary party and in absence of the purchasers, the effective judgment and decree cannot be passed. It is prerogative of the plaintiff to sue the person against whom he seeks relief. During the pendency of the suit, the son of the plaintiff sold the land in excess of his share but the court below has allowed the amendment petition but refused to implead the purchasers as defendants in the case. I find that the purchasers are necessary party but the learned Sub Judge has committed jurisdictional error in rejecting the petition