 As a result of this, he promptly resigned from the court which was effected in March.Khanna had previously authored the basic structure doctrine of the Constitution of India in "Kesavananda Bharati v. State of Kerala", which curtailed Parliament's seemingly unfettered amending power under article 368, restricting its scope of amendment in areas which were part of the Constitution's "basic structure".In addition, he delivered noted judgements in the Ahmedabad St. Xavier's College v. State of Gujarat (1974) and State of Kerala v. N. M. Thomas (1975) cases.