Orthodox Church leading a movement of fierce resistance.Archbishop Ieronymos II of Athens, the head of the church, said the measure sought only to "corrupt the homeland's social cohesion".Supporters of the church gathered in protest in Athens, many holding crosses and reading prayers in the capital's Syntagma Square.Dozens of ruling New Democracy party legislators were opposed to the bill, but support from opposition parties – notably the main opposition leftist Syriza party whose leader, Stefanos Kasselakis, is gay – meant it was certain to reach the simple majority needed to pass.LGBTQ+ organisations had argued that same-sex families faced a labyrinth of administrative challenges amounting to discrimination under present family law.When their children fall ill in Greece, non-biological parents currently have no right to decide what medical procedures are necessary for them, and children do not automatically inherit from their non-biological parents."This is a historic moment," Stella Belia, the head of same-sex parents' group Rainbow Families Greece, told Reuters news agency. "This is a day of joy."Once the law is promulgated, Greece will become the 16th member of the EU and the 37th country in the world to legalise same-sex marriage.