Japan’s ruling Liberal Democratic Party and its junior coalition partner, the Japan Innovation Party, have agreed with the opposition Democratic Party for the People to slash 31 proportional representation seats from the House of Representatives, aiming to pass the legislation during the current extraordinary parliamentary session ending December 12, 2026, according to the Hankyoreh.
The push to shrink the lower house marks a significant legislative shift. The change stems from a 12-point policy agreement struck last January when the Japan Innovation Party agreed to back Prime Sanae Takaichi’s coalition government on the condition that lawmakers pursue structural reform and cut political privileges.
While the original demand from the Japan Innovation Party sought a 10% reduction—roughly 45 seats—totaling the entire 465-member chamber, subsequent negotiations among the three parties dialed the target back to 31 seats. Under the agreed plan, the 289 single-member constituencies will remain untouched, while proportional representation seats will drop from 176 down to 145.
If enacted, this will represent the largest single reduction in the lower house since Japan introduced the parallel voting system combining single-member districts and proportional representation in 1994.
Securing the passage of the bill depends heavily on parliamentary arithmetic. The ruling LDP and Japan Innovation Party hold more than a two-thirds supermajority in the lower house, ensuring smooth sailing in that chamber. However, the ruling coalition falls about five seats short of a majority in the upper house, the House of Councillors, even with the support of pro-ruling independents.
That numerical gap gives the Democratic Party for the People crucial leverage, as the party can mobilize more than 20 votes in the upper house. Shinba Kazuya, secretary-general of the Democratic Party for the People, explained the rationale behind the compromise to reporters following the three-party agreement, stating that if they had not conceded to process the legislation, the ruling coalition would have pushed through a 45-seat reduction, which was not what the public or other opposition parties wanted, and that politics is the product of compromise.
Not all opposition factions share that pragmatic view. Other political groups have sharply criticized the deal, arguing that cutting seats exclusively from the proportional representation tier disproportionately penalizes smaller parties and benefits well-funded major organizations like the LDP that maintain robust local networks.
Hiromasa Nakano, policy research council chief for Komeito, voiced skepticism over the structure of the cuts in the party’s official publication, the Komeito Shimbun. He stated that reducing only proportional representation seats by 31 lacks persuasiveness, questioned whether there were underlying circumstances within the ruling parties preventing them from cutting single-member districts, and expressed a willingness to discuss the matter if there were a rational basis and the composition ratio between single-member districts and proportional representation was maintained at 3 to 2.
The Japanese Communist Party also condemned the maneuver, stating that a handful of parties bypassing wider opposition consensus to force through legislative changes using sheer voting power is entirely unacceptable.
| Chamber | Total Seats | Proposed Change |
|---|---|---|
| House of Representatives (Single-Member) | 289 | No change |
| House of Representatives (Proportional) | 176 | Reduced by 31 (to 145) |
| House of Councillors (Upper House) | 248 | No change |
The three participating parties intend to submit the electoral reform bill to the ongoing extraordinary Diet session with the objective of completing the legislative process before the session closes on December 12.
