A government panel has begun work toward redrawing the single-seat constituency boundaries in 10 prefectures for House of Representatives elections.
The Council on the House of Representatives Electoral Districts held its first meeting on Monday and began discussions based on recently released census data.
Discussion at the meeting focused on a scenario in which one electoral district is taken away from each of five of the 10 prefectures and added individually to the other five.
The census showed that the difference between the number of eligible voters in the five prefectures to lose a district -- Hokkaido, Yamagata, Shizuoka, Shimane and Oita -- and the number of eligible voters in the five to gain a district -- Saitama, Chiba, Kanagawa, Shiga and Okinawa -- has become wider.
It is believed that the discussed new district allocations would reflect this change.
The meeting marks the first time the council has discussed redrawing constituency boundaries since the current single-seat constituency system for Lower House elections was introduced in 1994.
The council is expected to submit a report to Prime Minister Yoshiro Mori within a year of Friday's release of census data by the Home Affairs Ministry regarding the number of eligible voters in each of the 300 Lower House single-seat constituencies.
According to the law, no constituency in the country should have more than double the number of eligible voters as another.
This year's census data, however, reveals that, in numerical terms, the largest single-seat constituency has 2.573 times more eligible voters than the smallest -- up from 2.137 times in the 1990 census.
The smallest is Shimane No. 3, with 236,103 eligible voters, while the largest is Kanagawa No. 7, with 607,520.
Of the 480 seats in the Lower House, 300 are elected through single-seat constituencies while 180 are chosen by proportional representation.