In July 2012, Mayor Giuliano Pisapia promised to introduce a formal register of same-sex civil unions for the city of Milan, the largest city in Northern Italy, which would be designed to afford some legal protections to same-sex couples who cohabit, but these would not be equivalent to marriage rights. A spokesman for the Roman Catholic Archdiocese of Milan responded by arguing there was a "risk that giving equal status to families based on marriage with those founded on civil unions will legitimise polygamy".