The Okinawa assembly has decided to hold a referendum on a plan to relocate a US base within the prefecture.
The vote will be held within 6 months of the official announcement.
The assembly approved the ordinance on Friday by a majority vote. The signatures of more than 90,000 supporters of a referendum were submitted to the prefecture last month.
Voters will be asked if they approve the plan to relocate the US Marine Corps Futenma Air Station within the island prefecture.
Members of the parties that support Governor Denny Tamaki voted in favor of the referendum. Tamaki won last month's gubernatorial election. He has pledged to block the relocation plan agreed between Japan and the US.
The Ishigaki City assembly passed a motion opposing a referendum earlier this month. Some of the 41 municipalities in the prefecture have not yet said if they will provide staff to conduct the poll.
The prefectural government says it will coordinate with the municipalities so that the referendum can be held across Okinawa.