Artic/e 7 An alien lawfully in the territory of a State may be expelled therefrom only in pursuance of a dccision reached in accordance with law and shall, cxcept where compelling reasons of national security otherwise require, be allowed to submit the reasons why he or she should not be expelled and to have the case reviewed by, and be represented for the purpose before, the competen! authority or a person or persons specially designated by the compctent authority. Individual or collective expulsion of such aliens on grounds of race, colour, religion, culture, descent or national or ethnic origin is prohibited.