TOKYO, Japan — Japan’s ultraconservative Sanseito Party is moving closer to the country’s ruling Liberal Democratic Party (LDP) in a calculated effort to secure policy victories and enhance its political credibility before the 2027 unified local elections.
Sanseito gained national attention during the 2025 House of Councillors election, where its “Japanese First” slogan resonated with voters concerned about Japan’s growing foreign population and dissatisfied with the LDP under former Prime Minister Shigeru Ishiba. Although the party performed strongly, its relationship with the ruling coalition remained distant after Prime Minister Sanae Takaichi led the LDP to a decisive victory in the February 2026 House of Representatives election.
Despite the ruling coalition lacking a majority in the upper house, meaningful cooperation with Sanseito failed to materialize earlier this year. However, recent developments suggest a significant political shift.
Sanseito recently supported a bill to reform Japan’s controversial retrial system, stepping in after the Democratic Party for the People (DPP) declined to back the legislation. The party also joined the LDP, its coalition partners, and the DPP in submitting a bill that would criminalize the desecration of Japan’s national flag.
One of Sanseito’s key policy demands was accepted by the ruling party, expanding penalties to include individuals displaying Japanese flags marked with a cross during political campaign speeches. The concession highlighted the growing willingness of the LDP to work with the smaller opposition party.
Earlier this year, relations between the two parties appeared strained. The LDP excluded Sanseito from a cross-party council discussing tax reduction measures, prompting Sanseito to oppose the 2026 national budget. Party leader Sohei Kamiya argued at the time that the overlap between Sanseito’s policies and those of the LDP was shrinking.
According to a senior Sanseito official, the recent change reflects a new attitude from the governing parties.
“The governing parties’ attitude is what has changed. Perhaps they have come to realize that Sanseito will cooperate when called on,” the official said, suggesting that additional legislative cooperation could follow.
Political analysts believe the warming relationship is partly driven by the upcoming unified local elections, which are viewed as a crucial opportunity for Sanseito to expand its regional influence. The party has announced plans to field approximately 600 candidates, demonstrating its ambition to transform from a niche nationalist movement into a broader political force.
As Japan’s political landscape continues to evolve, the growing cooperation between Sanseito and the LDP could reshape legislative negotiations and influence the country’s conservative agenda in the months leading up to the next round of elections.
