No person shall, except with the previous permission in writing of the competent authority, transfer or purport to transfer by sale, mortgage, gift, lease or otherwise any land or part thereof situated in the Union territory of Delhi, which is proposed to be acquired in connection with the Scheme and in relation to which a declaration to the effect that such land or part thereof is needed for a public purpose having been made by the Central Government under section 6 of the Land Acquisition Act, 1894 (1 of 1894), the Central Government has not withdrawn from the acquisition under section 48 of that Act.