A draft proposal to correct the sharp imbalances in the value of votes between constituencies in Upper House elections, recently put forward by the head of the council on the chamber's electoral system, calls for reorganizing electoral districts across prefectural borders and narrowing the maximum gap in the vote value to within 2 to 1. Lawmakers from both the ruling and opposition camps should use the proposal to expedite their discussions and come to an agreement so that they can implement the changes in time for the next Upper House election in 2016.
In the 2013 Upper House election, which chose half the current members of the chamber, the maximum disparity in the value of votes between populous and less populous constituencies reached 4.77 to 1, meaning that a vote in one electoral district carried 4.77 times the weight of a vote in another in electing lawmakers. In a series of 16 lawsuits filed over the vote-value disparity in the election, all of the high court rulings determined that the electoral system that allowed such a gap was either "unconstitutional" or "in a state of unconstitutionality." The October 2012 ruling by the Supreme Court on the 2010 Upper House election stated that an overhaul of the prefecture-based constituency system was needed to fundamentally correct the gap.
The draft plan by Masashi Waki, the ruling Liberal Democratic Party's secretary general for the Upper House, redraws the current constituencies based on the nation's 47 prefectures by creating 11 new electoral districts that straddle two prefectures. Under the proposal, the nation's population is divided by 73 — the number of Upper House members elected through constituency races every three years — and a constituency (prefecture) whose population falls short of the benchmark figure of 1.75 million will be combined with its neighboring constituencies.