In a setback to pro-reservationists, the Supreme Court on Thursday stayed the central law providing for 27 percent reservation for Other Backward Classes in elite educational institutions like IITs and IIMs.

The Court held that the 1931 census could not be a determinative factor for identifying the OBCs for the purpose of providing reservation.

"...it is desirable to put on hold the OBCs reservation," a Bench comprising Justice Arijit Pasayat and Justice L S Panta said.

However, it clarified that the benefit of reservation for the Scheduled Castes and Scheduled Tribes could not be withheld and the Centre can go ahead with the identification process to determine the backward classes.

The verdict was pronounced on a bunch of petitions challenging the Government notification to implement the controversial Central Educational Institution (Reservation in Admission) Act, 2006 providing 27 percent reservation to the OBCs in elite institutions.

"What may have been the data in 1931 census cannot be a determinative factor now," the Bench said disagreeing with the Centre's mode of selection of relevant data for providing reservation to the OBCs.

The Court said the State was empowered to enact an affirmative act to help the backward classes but this action could not be unduly adverse to those who were left out.

"Reservation cannot be permanent and appear to perpetuate backwardness," the Bench observed.

The Bench had on Wednesday questioned the government's decision as to how it could implement the policy without determination of the relevant data.

"Unless and until it is determined by the Centre who is socially and economically backward, this Act cannot really be given effect," the Bench had said as the anti-quota propagandists opposed its implementation on the ground that the 75-year-old census could not be the basis for identifying the OBCs.

The Centre, however, had maintained that implementing the provision of the newly-enacted legislation would not take away the rights of the General category candidates as adequate care has been taken by enhancing the seats proportionately.

Various organisations like the Residents Doctor Association, Youth For Equality, a forum of students and several others including educationists, had opposed the recently enacted legislation enabling 27 percent quota for the OBCs in the elite educational institutions.