Number of Lower House Seats: JIP’s Grounds for Reduction Far Too Unclear

Editorial

15:00 JST, November 4, 2025

Why is it necessary to reduce the number of seats in the House of Representatives? And why should the amount of the reduction be 10%?

It must be said that the Japan Innovation Party’s argument is really lacking in persuasiveness.

The Liberal Democratic Party has established a political system reform headquarters directly under its president. The headquarters will formulate a plan to reduce the number of lower house seats, which was included in the LDP-JIP coalition agreement based on the JIP’s strong demand for the reduction.

JIP leader Hirofumi Yoshimura has said, as the reason for reducing the number of seats, that it will be impossible to achieve bold reforms on such matters as social security systems if “self-sacrificing reforms” are not carried out.

Within the JIP, many voices argue that 50 seats should be cut from the proportional representation segment alone.

On its home turf, the party has in the past drastically reduced the number of seats in the Osaka prefectural assembly. Two years ago, it also reduced the number of seats in the Osaka City assembly. It appears that the JIP wants to bring this successful experience, which expanded public support for the party, to national politics.

However, unlike local assemblies, the Diet is the highest organ of state power, and Diet members are representatives of the Japanese people with whom sovereign power resides. Simply reducing the number of Diet seats would make it harder for voters’ voices to reach national politics.

Fundamentally, the current number of 465 seats in the lower house is almost the same level as the 466 seats immediately after World War II, when the nation’s population was just over 70 million. Compared to major European nations, Japan’s number of Diet seats is low relative to its population.

The JIP has said if it cannot submit a lawmaker-sponsored bill for reducing the number of seats jointly with the LDP during the current Diet session, the party will not hesitate to leave the coalition. However, elections are the foundation of representative democracy. The attitude of trying to decide the nature of elections based solely on their own assertions is too forceful.

With “reduction of the number of Diet seats during the current session as an absolute condition,” government administration will not proceed smoothly.

The reason that the JIP has gained support by advocating for a reduction in seats, in a show of “determination for self-sacrifice,” is likely that a spate of scandals and other issues involving lawmakers have given the impression that Diet members are steeped in vested interests.

It is true that Diet members must correct their conduct, but the issue of the appropriateness of lawmakers’ activities must not be mixed up with the question of the adequacy of the number of representatives for the people.

The problems that have to be corrected are not limited to the number of seats in the lower house.

To correct disparities in the value of votes, zoning of single-seat constituencies has repeatedly been redrawn, constantly reducing the number of lawmakers elected from rural areas. Many likely feel uneasy about the system in which candidates who lose in a single-seat constituency race in the lower house elections are then elected through proportional representation.

The House of Councillors also faces problems, such as low voter turnout in the prefectures in merged electoral constituencies. The time has come for ruling and opposition parties to cooperate and discuss the way elections should be, including the division of roles between the two chambers of the Diet.

(From The Yomiuri Shimbun, Nov. 4, 2025)