Sub-capital plan referendum provision draws constitutional challenge over expanded Osaka voter pool
Legal scholars say the sub-capital plan (副首都構想) bill’s clause to expand Osaka’s referendum electorate to prefecture residents may breach Article 92 of the Constitution.
The Liberal Democratic Party (LDP) and the Japan Innovation Party (Ishin) are advancing a bill tied to the government’s sub-capital plan that would allow a referendum on dissolving Osaka City and creating special wards to be conducted across the entire prefecture.
The provision would couple a possible renaming of the prefecture to a “metropolis” with a prefecture-wide vote on both the name change and the special-ward reorganization, a move critics say alters who gets to decide a city’s fate.
Text of the draft law and referendum mechanics
The bill under discussion stipulates that when a prefecture seeks to abolish a city and set up special wards as part of a bid to become a “metropolis,” a single referendum would decide both the ward reorganization and any change to the prefectural name.
Under that design, the electorate for the referendum could be extended beyond the city’s residents to include all eligible voters across the prefecture, effectively allowing prefectural voters to decide municipal governance matters.
Proponents argue the joint referendum is intended to address the cross-boundary fiscal and administrative effects of a metropolitan reorganization.
Opponents counter that bundling a name change with a municipal reorganization shifts the locus of decision-making away from the residents directly governed by the change.
Constitutional objections from legal scholars
Constitutional scholars who testified at an expert hearing convened by the LDP on June 10 warned that extending the referendum electorate may run afoul of Article 92, which guarantees local autonomy.
Professor Makoto Arai of Hiroshima University’s law faculty said the proposal risks violating both aspects of local autonomy: “resident self-government,” whereby inhabitants decide local matters, and “organizational autonomy,” which shields municipal entities from external interference.
Scholars pointed to a 1963 Supreme Court ruling that held the central government cannot use legislation to strip away constitutionally guaranteed local functions.
They argue that a law enabling prefecture-wide decisions on a single city’s internal structure would undermine the constitutional balance between national authority and municipal self-rule.
LDP amendment offered to limit referendum to city residents
Facing legal pushback, the LDP has proposed a revision that would limit referendum eligibility to the city’s residents alone, a change meant to address the constitutional concerns raised by experts.
The LDP’s leadership transmitted the amendment proposal to Ishin, but party officials say Ishin has so far declined to accept the limitation.
A face-to-face meeting between LDP leader and Prime Minister Sanae Takaichi and Ishin leader and Osaka Governor Hirofumi Yoshimura was scheduled for June 22, 2026 to discuss remaining differences.
Party sources indicate the talks will focus on whether the electorate question can be resolved politically or will require further legislative compromise.
Legal practitioners warn of wider precedent and call for repeal
A lawyers’ group active in Osaka, the Osaka branch of Jiyu Hosodan, has similarly flagged constitutional problems in the bill’s present form.
The organization warned that if the law stands, it could set a precedent allowing prefectural voters to dissolve other ordinance-designated cities nationwide through prefecture-wide referendums.
The group called on lawmakers to withdraw the contested provisions, arguing that the measure would create a structural tool for prefectural authorities to override municipal autonomy across Japan.
Civil society and legal observers caution that the stakes go beyond Osaka by potentially reshaping the legal boundaries of local self-governance.
Ishin’s rebuttal and political rationale
Ishin leader Hirofumi Yoshimura has publicly rejected the view that the bill is unconstitutional, saying on June 15 that questions about the referendum’s scope should be decided by statutory councils and by votes in both prefectural and municipal assemblies.
Yoshimura told reporters that there are legitimate arguments for both a city-limited and a prefecture-wide vote, and that the law’s design leaves room for the local statutory consultation process to set the final approach.
Ishin officials argue the sub-capital plan aims to tackle administrative fragmentation and regional competitiveness, and that flexible referendum rules are necessary to reflect the cross-jurisdictional impact of a metropolitan reorganization.
Critics counter that political convenience should not override constitutional protections for locally determined governance.
Legal remedies and likely next steps if the bill is enacted
Legal experts say that if the bill becomes law without amendment, affected parties could seek judicial review or injunctions to suspend a referendum on constitutional grounds.
Professor Arai warned that while courts are cautious about intervening in political decisions, there is precedent for judicial scrutiny where legislation appears to strip municipalities of their autonomous functions.
Political negotiators face a narrow window to reconcile the competing legal and political claims before any referendum timetable is set.
If lawmakers fail to find common ground, the dispute is likely to move from the Diet to the courts and could trigger broader debates about the constitutional limits of national authority over local governance.
The sub-capital plan’s contested referendum clause has thus become a focal point of a larger constitutional dispute, with lawmakers, legal experts and civic groups each staking out opposing positions over who should decide a city’s future.
