constitutes an unfair and exclusive advantage in favor of one or more specified person or persons to the detriment of the public in general or of any special class of society.
Associations of labor organized to protect their own interests shall not be deemed a monopoly. Nor shall coöperative associations or unions of producers be deemed monopolies when, in defense of their own interests or of the general public, they sell directly in foreign markets national or industrial products which are the principal source of wealth of the region in which they are produced, provided they be not necessaries, and provided further that such associations be under the supervision or protection of the Federal Government or of that of the States, and provided further that authorization be in each case obtained from the respective legislative bodies. These legislative bodies may, either on their own initiative or on the recommendation of the Executive, revoke, whenever the public interest shall so demand, the authorization granted for the establishment of the associations in question.
Art. 29. In cases of invasion, grave disturbance of the public peace, or any other emergency which may place society in grave danger or conflict, the President of the Republic of Mexico, and no one else, with the concurrence of the council of ministers, and with the approval of the Congress, or if the latter shall be in recess, of the Permanent
