Political parties and lawmakers should not sit idle in the wake of inconclusive high court rulings recently on whether the gap in vote value between electoral districts in the Lower House election in December violated the principle of equality under the Constitution. Although the courts delivered mixed decisions, the parties need to come to grips with the grave nature of the issue at stake — whether the popular will of voters is accurately represented in the Diet — and take swift action to correct the imbalances.

Right after Prime Minister Shinzo Abe's ruling coalition swept to a two-thirds majority in the Lower House in December's snap election, two groups of lawyers filed 17 lawsuits with high courts and their local branches seeking to invalidate the outcome of races fought in the chamber's 295 constituencies across Japan. In the election, the maximum gap in the value of votes between populous and less populous constituencies reached 2.13 to 1. Ballots cast by voters in the Miyagi No. 5 constituency had 2.13 times more weight in electing Lower House members than votes cast by people in Tokyo's No. 1 electoral district.

So far, rulings have been handed down in 14 of the 17 suits, with widely varying court decisions. The Fukuoka High Court, in its Wednesday decision, ruled that the elections in the constituencies of Fukuoka, Saga, Nagasaki, Oita and Kumamoto prefectures were "unconstitutional" but did not go as far as to invalidate the results. Vote-value disparity was judged to be "in a state of unconstitutionality" in nine other court decisions, while four courts ruled that the December election was "constitutional," noting that the gap in vote value was not as wide as to infringe on equality under the Constitution.