“Rules of natural justice are not embodied rules. Being means to an end and not an end in themselves, it is not possible to make an exhaustive catalogue of such rules. But there are two fundamental maxims of natural justice viz. (i) audi alteram partem, and (ii) nemo judex in re sua. The audi alteram partem rule has many facets, two of them being (a) notice of the case to be met; and (b) opportunity to explain. This rule cannot be sacrificed at the altar of administrative convenience or celerity. The general principle—as distinguished from an absolute rule of uniform application—seems to be that where a statute does not, in terms, exclude this rule of prior hearing but contemplates a post-decisional hearing amounting to a full review of the original order on merits, then such a statute would be construed as excluding the audi alteram partem rule at the pre-decisional stage. Conversely if the statute conferring the power is silent with regard to the giving of a pre-decisional hearing to the person affected and the administrative decision taken by the authority involves civil consequences of a grave nature, and no full review or appeal on merits against that decision is provided, courts will be extremely reluctant to construe such a statute as excluding the duty of affording even a minimal hearing, shorn of all its formal trappings and dilatory features at the pre-decisional stage, unless, viewed pragmatically, it would paralyse the administrative process or frustrate the need for utmost promptitude. In short, this rule of fair play must not be jettisoned save in very exceptional circumstances where compulsive necessity so demands. The court must make every effort to salvage this cardinal rule to the maximum extent possible, with situational modifications. But, the core of it must, however, remain, namely, that the person affected must have reasonable opportunity of being heard and the hearing must be a genuine hearing and not an empty public relations exercise.”