The bench also rejected the centre's contention that it was entitled to lay down policies involving union territory services and issue executive instructions under Article 239 of the Constitution.

'Both the central government and the state government indisputably may lay down a policy decision in regard to reservation having regard to Articles 15 and 16 of the Constitution of India but such a policy cannot violate other constitutional provisions. A policy cannot have primacy over the constitutional scheme,' it said.

The court agreed with the arguments of petitioners Subhash Chandra and Sarv Rural and Urban Welfare Society that a person belonging to a caste notified as Scheduled Caste in one state cannot automatically claim the benefit of any notification specifying a similar caste in another state or union territory.

'Persons belonging to a particular caste or tribe may suffer some disadvantages in one state but may not suffer the same disadvantages in the other. Our constitutional scheme, therefore, seeks to identify the social and economic backwardness of people having regard to the state or UT as a unit,' it said.

'When a person is held to be a member of Scheduled Caste for one state, he cannot be treated as such in another,' it added.