The Liberal Democratic Party, Nippon Ishin no Kai and the Democratic Party for the People agreed on a bill on the 9th to cut 31 of the 465 Lower House seats, all from proportional representation, and plan to submit it jointly within the week.
The three parties will move the bill through their internal procedures and aim to enact it in the current Diet session, which ends on December 12, toward taking effect in 2027. They already hold a majority in the Upper House, where the LDP governs as a minority.
The bill amends the Public Offices Election Act. It follows an agreement reached by the three parties' secretaries-general at the end of October.
What the bill changes
Alongside the seat cut, the bill switches the proportional formula to a modified Sainte-Laguë method, which makes it easier for mid-sized parties to win seats. It also merges the Chugoku and Shikoku proportional blocks.
- Introduces a unified list allowing multiple parties to share one proportional roster
- Raises the threshold for revival via the proportional block from one-tenth to one-sixth of valid votes
- Lowers the deposit forfeiture threshold
- Treats seats that move to another party when a party fields too few candidates as vacancies
The unified list was a DPFP proposal. The bill carries no concrete provisions for it, stating only that "necessary legislative measures shall be taken." Details will be discussed alongside the coming redrawing of single-seat districts.
Under current rules, parties can already pool their lists by forming a political organization together. But a candidate cannot run in a single-seat district while also appearing on another party's list.
A unified list would reduce wasted votes for small parties that struggle to win seats. How to allocate party subsidies remains unresolved.
Opposition pushback
Opposition parties objected to the bill. "Changing the rules out of nowhere, we cannot fight," one was quoted as saying, the Asahi Shimbun reported.