2. Migrant workers and members of their families shall have the right to be fully informed of the terms on which such temporary absences are authorized. Article 39 1. Migrant workers and members of their families shall have the right to liberty of movement in the territory of the State of employment and freedom to choose their residence there. 2. The rights mentioned in paragraph 1 of the present article shall not be subject to any restrictions except those that are provided by law, are necessary to protect national security, public order (ordre public), public health or morals, or the rights and freedoms of others and are consistent with the other rights recognized in the present Convention. Article 40 1. Migrant workers and members of their families shall have the right to form associations and trade unions in the State of employment for the promotion and protection of their economic, social, cultural and other interests. 2. No restrictions may be placed on the exercise of this right other than those that are prescribed by law and are necessary in a democratic society in the interests of national security, public order (ordre public) or the protection of the rights and freedoms of others. Article 41 1. Migrant workers and members of their families shall have the right to participate in public affairs of their State of origin and to vote and to be elected at elections of that State, in accordance with its legislation. 2. The States concerned shall, as appropriate and in accordance with their legislation, facilitate the exercise of these rights. Article 42 1. States Parties shall consider the establishment of procedures or institutions through which account may be taken, both in States of origin and 123