(1) In an urban area, no improvement shall be undertaken or carried out by any person or department of the Government unless-
(i) it is in accordance with the master plan where it is in operation; or
(ii) it is in accordance with the scheme sanctioned and notified under section 38; or
(iii) where neither any master plan nor any scheme is in force, it is according to the general approval of the Trust,
and unless permission for undertaking or carrying out such improvement has been obtained in writing under the provisions of section 73.
(2) No person or department of Government shall use or permit to be used any land or building in any urban area otherwise than in conformity with the master plan where it is in operation or with the scheme sanctioned and notified under section 38 or with the general approval of the Trust, and unless the permission of the Trust for such use has been obtained under section 73:
Provided that subject to the provisions of section 73B, it shall be lawful for any person or department to continue to use, upon such terms and conditions, as may be prescribed by regulations made in this behalf, any land or building for the purpose and to the extent for and to which, it is being used upon the date on which such plan or scheme comes into force or as the case may be, the area is declared as an urban area under this Act.