Japan top court rules 2025 election in unconstitutional state

The Supreme Court ruled Wednesday that the July 2025 Upper House election was conducted in an “unconstitutional state” due to vote-value disparities of up to 3.13.

The top court’s Grand Bench, presided over by Chief Justice Yukihiko Imasaki, issued the ruling on a total of 16 lawsuits filed by two groups of lawyers seeking to invalidate the election across the country. It dismissed requests to invalidate the election.

Imasaki said that the maximum disparity in the election was at a level that raises constitutional concerns. The ruling was backed by 10 of the 15 justices, while the other five found the 2025 election to be constitutional.

This is the first time the top court has found an Upper House election with a maximum vote-value gap of less than 4.00 to be held in an unconstitutional state. The court last recognized such a state for an Upper House election in 2013, when the maximum disparity was 4.77.

The 2025 election was held under the same framework as the previous poll in 2022. However, the maximum disparity rose to 3.13 from 3.03.

Prior to the top court’s decision, high court rulings were split on the lawsuits, with 11 finding the election to be in an unconstitutional state and five finding it constitutional.