law: The Delhi Municipal Corporation Act, 1957
  37. Discharge of functions of the Mayor by the Deputy Mayor.-
  (1) When the office of the Mayor is vacant, the Deputy Mayor shall act as Mayor until a new Mayor is elected.
  (2) When the Mayor is absent from his duty on account of illness or any other cause, the powers, duties and functions of the Mayor shall be exercised and performed by the Deputy Mayor.
  (3) The Mayor may by order in writing delegate any of his powers, duties and functions to the Deputy Mayor.