Notwithstanding anything contained in this Act, the Central Government may, at any time, without any formal investigation or inquiry, cancel or suspend any certificate granted by it under this Act, other than a certificate granted to a master, mate or engineer, if, in its opinion, the holder is, or has become, unfit to act in the grade for which the certificate was granted to him:
     Provided that no order under this section shall be passed by the Central Government unless the person concerned has been given an opportunity of making a representation against the order proposed.