"They can not hinder freedom of residence of a citizen of Union by denying grant to ir spouse, of same sex, national of a non-member State of Union, a right of permanent residence in ir territory", he says.
The finding involves the case of Romanian national Adrian Coman and his American partner, Clai Hamilton, who tied the knot in Brussels in 2010 but have since been denied the right to live in Romania together. The Romanian authorities said that Mr Hamilton could not be classified as a "spouse" because the country does not recognise same sex marriage.
ECJ Advocate General Melchior Wathelet said the term "spouse" included, under the freedom of residence of European Union citizens and their family members, spouses of the same sex.
He noted that "the directive makes no reference to member state law in order to determine the nature of "spouse", even though that concept must be interpreted autonomously and uniformly throughout the EU".
Concluding, he said: "In that context, the advocate general considers that, in view of the general evolution of the societies of the member states of the EU in the last decade in the area of authorisation of same-sex marriage. the term "marriage means a union between two persons of the opposite sex" can no longer be followed".
He noted that "same-sex marriage will be possible in Austria too", by this time next year.
If the ECJ does rule in the couple's favour it would pave the way for legal recognition of same-sex marriages to be expanded across Europe. Negative because country does not recognize homosexual marriage. We can hopefully now be closer to being recognised as a family.
Earlier in the opinion, Wathelet focus on one of the less traditional aspects of Coman and Hamilton's relationship. The couple, who met in NY in 2002 and are both 46, married in Belgium in 2010 after living together for four years in the US.
Wathelet said the pair should still be considered a family unit. They would have been compelled to do so had Mr Coman's partner been of the opposite sex. "The fact that the couple do not live together can not in itself have any effect on the existence of a proven stable relationship - which is the case - and, consequently, on the existence of a family life".