The introduction of PIL in India was facilitated by the relaxation of the traditional rule of ‘locus standi’. According to this rule, only that person whose rights are infringed alone can move the court for the remedies, whereas, the PIL is an exception to this traditional rule. Under the PIL, any public-spirited citizen or a social organisation can move the court for the enforcement of the rights of any person or group of persons who because of their poverty or ignorance or socially or economically disadvantaged position are themselves unable to approach the court for the remedies. Thus, in a PIL, any member of the public having ‘sufficient interest’ can approach the court for enforcing the rights of other persons and redressal of a common grievance.

Source: Laxmikanth