Japan’s Ruling LDP-JIP Coalition Shows Signs of Strain as Diet Seat Reduction Plan Fails to Advance

By Yuta Abe and Takahiro Yamamoto / Yomiuri Shimbun Staff Writers

15:36 JST, December 17, 2025

The two-month-old coalition government of the Liberal Democratic Party and the Japan Innovation Party is already showing signs of instability.

The parties agreed Tuesday to carry over their proposed bill to reduce the number of House of Representatives seats — a matter seen as a litmus test for the coalition’s future — to the next Diet session after failing to enter it into deliberation during the latest session.

They were ill-matched the whole time, as the LDP found itself scrambling to coordinate with the JIP, which was eager to push the bill through.

Frustration among JIP

“I think ‘unable to decide’ is not the same as ‘not decide,’” JIP leader Hirofumi Yoshimura said Tuesday after an LDP-JIP leaders meeting in the Diet building, revealing his dissatisfaction that the bill was not even put up for deliberation.

It was the fourth such face-to-face meeting between Prime Minister Sanae Takaichi and Yoshimura since the coalition agreement. These meetings have often been arranged by the LDP to persuade the JIP.

Even from their first meeting on Oct. 20, the two leaders managed to form a coalition after the LDP responded the JIP’s insistent demand for the bill’s passage in this Diet session with less clear wording: The government “would aim for passage” of the bill.

The talks ended with only a pledge to “aim for” passage, as the LDP expected. This prompted complaints within the JIP, with a senior member saying: “It was a tough result. The time was also too short.”

Acting like opposition party

The JIP, which prides itself as the key player behind the birth of the Takaichi Cabinet, rushed to build achievements during this Diet session. This urgency stemmed from public opinion polls showing the Takaichi Cabinet maintaining high approval ratings, although the JIP’s own ratings failed to rise even after joining the coalition.

Bolstered by its success in gaining public support by cutting the number of seats in the Osaka prefectural assembly, the JIP pressured the LDP by saying that cutting the number of lower house seats is the “heart” of the coalition.

Even when the LDP countered that “the situation differs between local assemblies and the Diet under the parliamentary cabinet system,” the JIP has kept advocating for “self-sacrificing reforms.”

The LDP has grown sour on the JIP, which offers its support from outside the Cabinet and occasionally hints at withdrawal from the coalition.

The JIP proposed a bill for “a reduction of 50 seats in the proportional representation segment alone” and insisted that the cut would be automatically confirmed if ruling and opposition parties failed to reach an agreement on the matter within a year. The LDP strongly objected to this demand, with one mid-ranking member saying: “Strong words do not make things happen. It acts just like an opposition party.”

At that time, a top-level meeting was arranged for Dec. 1, where Takaichi and Yoshimura sorted out the situation by presenting a provision for “a reduction of 25 seats in single-seat constituencies and 20 in the proportional representation segment” if the ruling and opposition parties do not agree on concrete measures within a year.

Time runs out

The LDP’s lack of enthusiasm was conspicuous once the bill was submitted to the lower house on Dec. 5, as it appeared from the outset that it would be difficult under Diet rules to refer the bill to the lower house’s Special Committee on Political Reform for deliberation.

On top of that, the Rules and Administration Committee, which decides on referrals, is evenly split between ruling and opposition party members, and the reform committee already had three bills under discussion related to the reform of political donations from companies and groups.

The JIP has few lawmakers who are well-versed in the procedural minutiae of Diet operations, with the exception of Diet affairs committee chairman Takashi Endo, who is a special adviser to the prime minister.

When Yoshimura criticized the opposition for “desperately thinking of reasons not to cut the number of seats,” a senior LDP official responded coldly, “Mr. Yoshimura, who has only 10 months of experience as a lower house member, should keep quiet.”

Toward the end of the Diet session, Takaichi, who could not bear to see the situation, requested the LDP leadership to allow the “JIP to save face.”

In response, LDP Secretary General Shunichi Suzuki hinted at an extension of the Diet session, exhibiting concern for the JIP. However, time ran out, and the Takaichi-Yoshimura meeting was held Tuesday.

The LDP cleared a major hurdle in this session by passing the fiscal 2025 supplementary budget, but its coordination with the JIP left lingering concerns for the future.

There are opinions within the LDP that “the JIP is an unstable coalition partner,” and some express hope for the Democratic Party for the People to join the coalition, as they take a favorable view of its support for passage of the supplementary budget.