law: 10. Restrictions respecting right to from associations, freedom of speech, etc.-
  (1) No member of the Group shall, without the previous sanction in writing of the Central Government or of the prescribed authority,-
  (a) be a member of, or be associated in any way with, any trade union, labour union, political association or with any class of trade unions, labour unions or political associations; or
  (b) be a member of, or be associated in any way with, any society, institution, association or organisation that is not of a purely social, recreational or religious nature; or
  (c) communicate with the press or publish or cause to be published any book, letter or other document except where such communication or publication is in the bona fide discharge of his duties or is of a purely literary, artistic or scientific character or is of a prescribed nature.
  Explanation.-If any question arises as to whether any society, institution, association or organization is of a purely social, recreational or religious nature under clause (b) or whether any book, letter or document is a communication or publication in the bona fide discharge of his duties or is a purely literary,
  artistic or scientific character or is of a prescribed nature under clause (c), the decision of the Central Government thereon shall be final.
  (2) No member of the Group shall participate in, or address, any meeting or take part in any demonstration organised by anybody of persons for any political purposes or for such other purposes as may be prescribed.