The Supreme Court today deferred till August 7 the hearing of the central government's plea seeking vacation of an interim order staying the implementation of the 27% reservation for OBCs in elite educational institutions.A bench headed by Chief Justice K G Balakrishnan said the government's application will be heard by a five-judge Constitution bench, which will also hear the main petition on the constitutional validity of the controversial act providing a quota for OBCs.The court had earlier fixed August seven as the date for examining the constitutional validity of the Central Educational Institutions (Reservation in Admission) Act 2006, which provides reservations for OBCs.