"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.
Advocates general's opinions are not binding, but the court often rules the same way as the advocate general.
The case involved Romanian Adrian Coman and American Clai Hamilton, who married in Brussels in 2010.
Romania has laws that prohibit the marriage of same sex couples, and doesn't recognise them at all in the legal system - resulting in the Romanian nationals spouse being unable to take up residence as the spouse of an European Union citizen.
Hearing a plea of unconstitutionality raised in the context of that dispute, the Curtea Constituţională (Constitutional Court, Romania) asked the European Court of Justice whether Mr Hamilton, as the spouse of an EU citizen having exercised his freedom of movement, must be granted a right of permanent residence in Romania. The Luxembourg-based court but not always follows the legal opinions of its advocates general.
That request was based on the directive on the exercise of freedom of movement, which permits a spouse of an European Union citizen who has exercised that freedom to join his or her spouse in the member state where the latter resides. While member states are free to provide for marriage between persons of the same sex in their domestic legal system or not, they must fulfil their obligations under the freedom of movement of European Union citizens.More news: Oprah Winfrey 'actively considering' running for President
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The rights of same-sex spouses have to be recognised by every member of the European Union, even if a nation's government does not permit gay marriage, the European Court of Justice (ECJ) has been advised. The couple challenged the decision in Romania's constitutional court, saying it was discriminatory on the grounds of sexual orientation.
"Romanian citizens can not be divided into good and gay".
A senior adviser to the European Union's top court has backed a Romanian gay man's right to have his USA husband live with him in Romania.
If Coman's bid is successful, the ruling would be controversial in Romania, where United States evangelicals have pushed a law to ban same-sex marriage.
Bulgaria, Latvia, Lithuania, Poland, Romania and Slovakia have no legislation on the matter - while Austria, Croatia, Cyprus, Greece, Hungary, Malta, Slovenia, the Czech Republic and Estonia all allow some form of civil partnerships.