( 1 ) THE challenge in this bunch of writ petitions, which are being decided by a common judgment, is to the increase by the respondents, with retrospetive effect, of the premium payable by the petitioners for the land altted to them by the Delhi Development Authority.

( 2 ) THE petitioners are various societies which have been set up for the purposes of establishing educational institutions. The educational institutions which are proposed to be set up by them are unaided schools within the meaning of that expression in the Delhi Education Act.

( 3 ) THE petitioners, at various points of time, had applied to the Delhi Development Authority for allotment of land. The land is to be allotted by the Delhi Development Authority under the provisions of D. D. A. Nazul Land Rules, 1989. The applicants are required to file a detailed application for allotment of land. The applications so received are forwarded to the Delhi Admininstration, who scrutinise the same from various angles and it is only after the Delhi Administration makes its recommendations that the Delhi Development Authority considers allotment of land to the various applicants for setting up educational instit