Reduction of Lower House Seats: Irrational Argument Contradicts Basic Tenets of Constitutional Politics

Editorial

15:09 JST, December 6, 2025

The ruling coalition intends to reduce the number of seats in the House of Representatives, no matter what, if ruling and opposition parties cannot agree on a reform proposal within a period that the coalition unilaterally sets.

It is startling that the ruling parties, which hold the responsibility of governing, submitted such a reckless bill. It will likely raise questions about their judgment.

The Liberal Democratic Party and its coalition partner the Japan Innovation Party have submitted a bill that outlines procedures for reducing the number of lower house seats.

According to the bill, the goal is to reduce the current 465 seats by 10%, with a reduction of at least 45 seats. It states that a council involving all ruling and opposition parties will discuss the matter, including how to revise the electoral system, but it also states that if the council fails to reach a conclusion within one year, the seat reduction will proceed automatically.

The bill also explicitly sets specific reduction numbers: Assuming the current election system, which combines single-seat constituencies and the proportional representation segment, remains in place, 25 seats representing single-seat constituencies will be cut, along with 20 seats in the proportional representation segment.

The nature of the electoral system is the very foundation of democracy. Issues such as the number of Diet seats should be decided through a broader consensus between ruling and opposition parties. Disregarding such procedures could undermine the authority of the legislature.

The provision to automatically reduce the number of lower house seats was included at the request of the JIP, which advocates “self-sacrificing reform.” It would be a grave mistake to assume that simply joining the ruling coalition allows a party to push through policies exactly as it likes.

Opposition to the bill emerged even within the LDP, with some members criticizing that “the seat reduction is advanced in too reckless a manner.” Yet the LDP dared to submit the bill, likely because it aimed to prevent the JIP from leaving the coalition.

It is disappointing that, despite being aware that there are problems with the bill, the LDP prioritized maintaining the coalition.

With the arrival of an era of multiparty politics, the LDP, as the largest party in the Diet, is almost sure to face more situations in which it must accept demands from smaller parties.

However, it goes against the fundamental principles of constitutional politics that smaller parties, which cannot be said to reflect the will of the majority, advocate extreme assertions, confuse major parties and influence the outcome of crucial issues concerning the very foundations of democracy.

Looking at the precarious relationship between the LDP and the JIP, it becomes clearer than ever how the longstanding cooperative coalition relationship between the LDP and Komeito paid careful attention to political affairs and Diet management.

Fundamentally, the number of lower house seats remains at almost the same level as immediately after the end of World War II, at 466, when the population was just over 70 million. In terms of population ratio, it is smaller than in other major countries. How can reducing the number of seats and diminishing the representation of the people be called reform?

In addition, many Diet members already serve as members of multiple committees. Further reducing the number of seats could hinder Diet functions such as enacting laws and overseeing the administration.

(From The Yomiuri Shimbun, Dec. 6, 2025)