The Alliance Defending Freedom, an extremist U.S.-based legal group that the Southern Poverty Law Center calls "virulently anti-gay," announced this week that they've been given permission to intervene as a third party in a lawsuit challenging Italy's discriminatory marriage laws.

From the group's press release:

"The people of Italy recognize that men and women bring distinct, irreplaceable gifts to family life, especially for children who deserve both a mom and a dad," said Senior Legal Counsel Roger Kiska. "Under the European Convention of Human Rights, the Strasbourg court is obliged to allow Italy to define marriage in a manner consistent with this truth. This lawsuit is asking the court to step outside of its bounds and impose a redefinition of marriage upon a Council of Europe member state that has exclusive authority over marriage within its own borders. The court should reject this request."

The case, Orlandi v. Italy, began after the Italian government denied a marriage license to two members of the same sex who applied for one. The case made its way through Italy's courts, which all upheld the country's marriage laws. The same-sex couple then filed a lawsuit with the European Court of Human Rights.

The Alliance Defending Freedom brief examines previous European Court of Human Rights positions on the matter, the treatment of marriage in the domestic laws of other nations, the sociological theory behind the definition of marriage and family, and the harms that could come as a result of redefining marriage under the European Convention on Human Rights.

"With regard to sensitive moral and cultural questions, among which the definition of marriage would certain fall, this Court has found it appropriate to cede authority over such issues to Member States themselves exclusively," the brief states. "The Court has held that it could not impose a single moral code over Europe regarding issues of ethical controversy where the opinions among Member States are so diverse."