Hungary plans to hold a referendum on legislation that limits schools’ teaching about homosexuality and transgender issues late this year or early next year, Prime Minister Viktor Orban’s chief of staff said on Thursday. Orban announced the referendum on Wednesday, stepping up a culture war with the European Union. The European Commission last week began legal action over the measures, which have been included in amendments to education and child protection laws. If successful, Brussels could hold up funding for Hungary while the restrictions are maintained. “For Hungary, there are many more arguments in favor of European Union membership than against it. Joining the EU was the right decision, it was in our national interest and it remains to be the case,” Gergely Gulyas, Orban’s chief of staff, told a weekly news briefing. But he said Hungary believed it had the right to comment on what he called “the rules …