(1) At any time after a housing scheme has come into force and before it is fully executed, the Board may for reasons to be recorded alter or cancel it:
Provided that-
(a) before making any alteration in a housing scheme which involves acquisition, otherwise than by agreement, of any land or building not proposed to be acquired in the original scheme, the Board shall serve a notice, in such form, on such persons or classes of persons and in such manner, as may prescribed, of the proposed alteration, and consider the objection, if any, received in pursuance of the notice within thirty days from the service of the notice or within such further time as the Board may, for sufficient cause, allow, and give an opportunity of being heard to the objectors;
(b) no scheme shall be altered or cancelled without the previous sanction of the State Government.
(2) Any alteration or cancellation of a scheme under sub-section (1) shall be notified in the Gazette and have effect from the date of such notification, so, however, that any such modification shall be without prejudice to the validity of anything previously done under the original scheme.