OOP is a concept where a person holds a political office that is paid. This concept first originated in England. Art. 102(a) of the Indian constitution bars a member of the Indian parliament from holding an OOP. In 2006 under political pressure, INC President and MP, Sonia Gandhi resigned several posts that were declared as OOP.
In Ashok Kumar Bhattacharya vs. Ajoy Biswas case the SC held that the question whether a person holds an OOP has to be interpreted based on the facts and circumstances of each case and the relevant statutory provisions.
The objective of the provision is to reduce conflict between duty and self interests among MPs. The expression OOP has not been defined in the constitution or in the representation of the people Act 1951. Over the years courts have decided this issue in the context of specific factual situations.
Unlike in India, In England whenever a new office is created the law also lays down whether it would be an OOP or not.