The International Convention on the Protection of the Rights of all Migrant Workers and Members of their Families was adopted by the United Nations General Assembly in Resolution 45/158 on 18 December 1990 but at the time of writing has not received enough ratifications to enter into force.

As of 23 September 2002, the following 19 states had ratified the Convention: Azerbaijan, Belize, Bolivia, Bosnia & Herzegovina, Cape Verde, Colombia, Ecuador, Egypt, Ghana, Guinea, Mexico, Morocco, Philippines, Senegal, Seychelles, Sri Lanka, Tajikistan, Uganda and Uruguay. Up-to-date information about ratification of the Convention can be found at: http://www.migrantsrights.org/Ratificationchart.htm

The Convention contains numerous provisions concerning the language rights of migrant workers and their families.

Article 1 

1. The present Convention is applicable, except as otherwise provided hereafter, to all migrant workers and members of their families without distinction of any kind such as sex, race, colour, language, religion or conviction, political or other opinion, national, ethnic or social origin, nationality, age, economic position, property, marital status, birth or other status.

Article 7 

States parties undertake, in accordance with the international instruments concerning human rights, to respect and to ensure to all migrant workers and members of their families within their territory or subject to their jurisdiction the rights provided for in the present Convention without distinction of any kind such as sex, race, colour, language, religion or conviction, political or other opinion, national, ethnic or social origin, nationality, age, economic position, property, marital status, birth or other status.

Article 16 

5. Migrant workers and members of their families who are arrested shall be informed at the time of arrest as far as possible in a language they understand of the reasons for their arrest and they shall be promptly informed in a language they understand of any charges against them...

8. Migrant workers and members of their families who are deprived of their liberty by arrest or detention shall be entitled to take proceedings before a court, in order that the court may decide without delay on the lawfulness of their detention and order their release if the detention is not lawful. When they attend such proceedings, they shall have the assistance, if necessary without cost to them, of an interpreter, if they cannot understand or speak the language used.

Article 18 

3. In the determination of any criminal charges against them, migrant workers and members of their families shall be entitled to the following minimum guarantees: (a) To be informed promptly and in detail in a language they understand of the nature and cause of the charge against them;...
(f) To have the free assistance of an interpreter if they cannot understand or speak the language used in court;

Article 22 

2. Migrant workers and members of their families may be expelled from the territory of a state party only in pursuance of a decision taken by the competent authority in accordance with law.

3. The decision shall be communicated to them in a language they understand.

Article 33 

1. Migrant workers and members of their families shall have the right to be informed by the state of origin, the state of employment or the state of transit as the case may be concerning: (a) Their rights arising out of the present Convention;
(b) The conditions of their admission, their rights and obligations under the law and practise of the state concerned and such other matters as will enable them to comply with administrative or other formalities in that state.
2. States parties shall take all measures they deem appropriate to disseminate the said information or to ensure that it is provided by employers, trade unions or other appropriate bodies or institutions. As appropriate, they shall co-operate with other states concerned.

3. Such adequate information shall be provided upon request to migrant workers and members of their families, free of charge, and, as far as possible, in a language they are able to understand.

Article 45 

2. States of employment shall pursue a policy, where appropriate in collaboration with the states of origin, aimed at facilitating the integration of children of migrant workers in the local school system, particularly in respect of teaching them the local language.

3. States of employment shall endeavour to facilitate for the children of migrant workers the teaching of their mother tongue and culture and, in this regard, states of origin shall collaborate whenever appropriate.

4. States of employment may provide special schemes of education in the mother tongue of children of migrant workers, if necessary in collaboration with the states of origin.

The full text of the International Convention on the Protection of the Rights of all Migrant Workers and Members of their Families can be found on the Internet site of UNESCO.