The so-called "right to self-determination" doesn't exist in the Spanish Constitution, nor in the International Law, nor in Comparative Law.
https://elpais.com/elpais/2014/10/10/opinion/1412946101_9911...
https://elpais.com/elpais/2014/10/10/opinion/1412946101_9911...
- Charter of the United Nations, Chapter 1 (Purposes and Principles), article 1.2: "To develop friendly relations among nations based on respect for the principle of equal rights and self-determination of peoples, and to take other appropriate measures to strengthen universal peace" [1]
- International Covenant on Economic, Social and Cultural Rights, article 1.1 (check out other points and article 2): All peoples have the right of self-determination. By virtue of that right they freely determine their political status and freely pursue their economic, social and cultural development. [2]
- International Covenant on Civil and Political Rights, article 1.1: [pretty much same text as International Covenant on Economic, Social and Cultural Rights) [3]
- Spanish Constitution, part 1 (Fundamental Rights and Duties), Section 10.2: "Provisions relating to the fundamental rights and liberties recognized by the Constitution shall be construed in conformity with the Universal Declaration of Human Rights and international treaties and agreements thereon ratified by Spain." [4]
Though you only had to check Wikipedia: "The right of people to self-determination is a cardinal principle in modern international law (commonly regarded as a jus cogens rule)" [5]
[1] http://www.un.org/en/sections/un-charter/chapter-i/index.htm...
[2] http://www.ohchr.org/EN/ProfessionalInterest/Pages/CESCR.asp...
[3] http://www.ohchr.org/EN/ProfessionalInterest/Pages/CCPR.aspx
[4] http://www.lamoncloa.gob.es/lang/en/espana/leyfundamental/Pa...