A high court ruled Wednesday that the gap in the weight of votes in last October’s Lower House election amounted to “a state of unconstitutionality,” despite previous high court rulings accepting the level of disparity.

Of the 14 lawsuits dealing with the weight disparities of up to 1.98 in the House of Representatives election, the Nagoya High Court is the first court to rule the vote gap was not in accordance with the one-equal-vote-per-voter principle protected under the Constitution.

The defendants — the election commissions of Gifu, Aichi, and Mie prefectures — insisted they narrowed vote weight disparities to under twofold in accordance with earlier rulings by the Supreme Court. The top court had said that general elections with disparities greater than twofold were in “a state of unconstitutionality.”

But the presiding Judge, Masayuki Fujiyama, said the Supreme Court’s rulings cannot be interpreted as approving disparities of less than twofold.

The October election was held “in a state that contradicted the equality of voting weight ensured under the Constitution,” Fujiyama said.

He also said constitutionality should be determined by considering the degree and causes of gaps in the weight of votes, even if disparities are kept under twofold.

In contrast, 10 other high courts have ruled that the disparities of less than twofold in the election were constitutional, noting that steps had been taken to narrow such gaps.

The lawsuits were filed by two groups of lawyers nationwide, challenging all of the 289 single-seat electoral district results.

Japan introduced single-seat electoral districts coupled with proportional representation in 1994. General elections held under the system in 2009, 2012 and 2014 had vote disparities of between 2.13 to 2.43, leading the Supreme Court to rule that they were “in a state of unconstitutionality” but not in effect unconstitutional or needing to be invalidated.

In 2016 and 2017, the state redrew electoral districts to slash one seat each in six prefectures and managed to reduce weight disparities in the election last year to under twofold for the first time.