This is a significant case, since it relates to discrimination on the grounds of sexual orientation in respect of legal differences between 'civil partnerships' and marriage.
The Court has previously held (in Schalk and Kopf v Austria, Gas and Dubois v France, and X. and Others v Austria) that when a Contracting State chooses to provide same-sex couples with an alternative means of legal recognition to marriage, it enjoys a certain margin of appreciation as regards the exact status conferred.
The applicants in Vallianatos and Mylonas v Greece and C.S. and Others v Greece are eight Greek nationals who live in Athens and an association with its registered office in Athens. Some of the applicants live together as couples, while others are in a relationship but do not live together.
The complaint relates to Greek law no. 3719/2008, which entered into force in November 2008. It made provision for the first time in Greece for an official alternative to marriage, in the form of 'civil unions' (σύμφωνο συμβίωσης). Such unions are reserved exclusively to two different-sex adults. Civil unions are entered into by means of a notarial instrument registered with the civil registry.
Relying on Article 8 of the Convention, taken alone and in conjunction with Article 14 of the Convention, the applicants complain that the Law, which limits civil unions exclusively to adults of different sex, breaches their right to respect for their private life and the principle of prohibition of discrimination. Under Article 13 of the Convention, the applicants further complain of the absence of an effective remedy in domestic law by which to assert their complaints concerning the alleged violation of Articles 8 and 14 of the Convention before the domestic courts.
The original communication can be found here (in French only): http://hudoc.echr.coe.int/sites/eng/pages/search.aspx?i=001-113205
The relinquishment to the Grand chamber in September 2012 can be found here: