Reiwa 7 (Gyo-Ke) No. 1 Population Ratio Election Lawsuit

This case challenges the constitutionality of the October 2024 Japanese general election for the House of Representatives. Plaintiffs argued that the maximum vote-value disparity among electoral districts reached approximately 2.06-to-1, violating the principle of equality under Article 14, the right to vote under Article 15, and the requirement for fair representation under Article 43 of the Constitution. They sought invalidation of the election in severely malapportioned districts. The Supreme Court’s Grand Bench reviewed the legislative framework and the Diet’s ongoing redistricting efforts. The Court found the disparity to be in an unconstitutional state but declined to void the election results, applying the “circumstances judgment” doctrine and giving the Diet a further opportunity to correct the imbalance.

The Supreme Court ruled the disparity was in an unconstitutional state but did not invalidate the election. It urged the Diet to promptly achieve a disparity below 2.0 through comprehensive electoral reform, continuing a pattern of remedial warnings without immediate election nullification.

Whether a maximum vote-value disparity of around 2.06 in the October 2024 House of Representatives election violated constitutional equal protection and fair representation clauses, and whether the election results should be invalidated as a remedy.

The ruling reignited public and political debate on fundamental electoral reform, including the possibility of a full constitutional amendment or a shift to a mixed-member proportional system. It underscored the persistent gap between judicial admonitions and legislative action, eroding some public confidence in the court’s willingness to enforce voting equality.