Photo/Illutration A resident walks past campaign posters set up in Kanagawa Prefecture for the November 2021 Lower House election. (Asahi Shimbun file photo)

The Diet passed legislation Nov. 18 that will reapportion Lower House seats, giving urban prefectures more seats while taking away the same number from rural regions, to help reduce a vote-value disparity that is the subject of lawsuits every time a national election is held.

The bill to revise the Public Offices Election Law passed the Diet with Upper House approval and will be enacted in about a month. The changes in districting will take effect from the next Lower House election.

Under the changes, the vote disparity between the least and most populous prefectures will be reduced from 2.096 times to 1.999 times.

Five prefectures will gain a total of 10 seats, with Tokyo getting five more, Kanagawa Prefecture receiving two and Saitama, Chiba and Aichi prefectures gaining one seat each.

On the other hand, 10 prefectures losing one seat each will be Miyagi, Fukushima, Niigata, Shiga, Wakayama, Okayama, Hiroshima, Yamaguchi, Ehime and Nagasaki.

In addition, there will be changes in the distribution of seats in the proportional representation regional blocs, with the Tokyo bloc gaining two seats and the Minami-Kanto bloc adding one seat. The blocs of Tohoku, Hokuriku-Shinetsu and Chugoku will lose one seat each.

The reapportionment will represent a major headache for the ruling Liberal Democratic Party in deciding which lawmakers to endorse in single-seat districts. In the prefectures of Yamaguchi, Shiga, Okayama and Ehime where one seat each will be subtracted, LDP lawmakers hold all the current seats.

The LDP will also have to negotiate with junior coalition partner Komeito about which party will be allowed to run candidates in the five new districts to be established in Tokyo.

Komeito until now has only run a candidate in the Tokyo No. 12 district, while the LDP has refrained from fielding a candidate there as a courtesy.

But because Komeito has a strong overall base in the capital, party officials are eager to field another candidate in one of the new districts. LDP officials also are eying those new districts as possible gains for their party.

The new law will also redraw district lines in 140 districts over 25 prefectures.