Section 351(1A)(a) in The Mumbai Municipal Corporation Act, 1888
(a)by written notice, require the person who is erecting such building or executing such work, or has erected such building or executed such work, [or who is the owner for the time being of such building or work] [These words were inserted by Bombay 64 of 1953, Section 14.], [within seven days from the date of service of] [These words were substituted for the words 'on or before such days as shall be specified in' by Maharashtra 10 of 1998, Section 143(b).] such notice, by a statement in writing subscribed by him or by an agent duly authorized by him in that behalf and addressed to the [Designated Officer] [These words were substituted for the word 'Commissioner' by Maharashtra 2 of 2012, Section 3(2) dated 13-3-2012.], to show sufficient cause why such building or work shall not be removed, altered or pulled down; or