With the current parliamentary session set to end in about two weeks, political tugs-of-war within the ruling Liberal Democratic Party and the opposition Constitutional Democratic Party of Japan are intensifying over the question of a snap Lower House election on the same day as next month’s scheduled Upper House poll.

While CDP leader Yoshihiko Noda has not yet declared whether his party would back a no-confidence motion and Prime Minister Shigeru Ishiba has not publicly stated he will dissolve the Lower House if one is submitted, a double election could result in more political stability if either party manages to capture both chambers, or continued instability if neither holds a majority, even in a coalition.

If the opposition parties in the Lower House, which hold a majority, pass a no-confidence motion against the Cabinet, Ishiba and his Cabinet must resign en masse. A new prime minister can be chosen and form a new Cabinet, unless the Lower House is dissolved within 10 days, according to Article 69 of the Constitution.

A Lower House election must then be held within 40 days. The current session of parliament is scheduled to finish on June 22.

On the other hand, the prime minister could unilaterally dissolve the Lower House to call a snap election at the time of his choice, even before the motion is voted on.

Reports last week indicated Ishiba had not ruled out dissolving the lower chamber if a no-confidence motion were to be submitted. On June 5, Nippon Ishin no Kai co-leader Seiji Maehara, who has a good personal relationship with Ishiba, said the prime minister told him privately parliament would be dissolved in that event.

Other members of his party are not denying the possibility. LDP Secretary-General Hiroshi Moriyama told reporters on June 3 he had not discussed this with Ishiba, saying only that the prime minister will make an appropriate decision at the appropriate time.

Speaking on Fuji TV on Sunday morning, former Prime Minister Fumio Kishida, who backed Ishiba in last September’s LDP presidential election, said the decision to dissolve parliament was one of political life or death for any prime minister.

“So I believe that we have no choice but to respect Prime Minister Ishiba's decision,” Kishida said.

Dissolution would be risky for the unpopular LDP. A June 7-8 Asahi News Network poll showed the Ishiba Cabinet support rate at 34.4%, a 6.8 point rise over last month, while 72% of respondents approved of agriculture minister Shinjiro Koizumi’s efforts to bring down rice prices.

The LDP might agree to a quick Lower House election in the hope of utilizing Koizumi’s popularity to garner voter support. But the same poll showed that 46.4% of respondents did not support the Cabinet. There is no guarantee that voters, regardless of their views on Koizumi, would cast their ballots for other LDP candidates and once again give the party a majority in the Lower House.

As the main opposition party, the CDP’s backing of a no-confidence motion would be crucial for it to pass. Yuichiro Tamaki, leader of the smaller Democratic Party for the People, said Sunday he wanted to speak with Noda about the issue before considering the DPP’s position. Powerful CDP veteran Ichiro Ozawa strongly supports submitting a no-confidence motion.

“It’s only natural that a motion of no confidence should be submitted at the end of the Diet session, and there should be no hesitation in doing so,” he said on his YouTube channel Saturday.

The CDP went from 98 to 148 Lower House seats in the October 2024 election, but that's still well short of the 233 minimum needed for a majority. Given the party’s struggles to gain traction with voters and a split opposition camp, it, too, faces a political risk by pushing a no-confidence vote, as it’s not clear whether the CDP could win an outright majority in a Lower House election or what kind of ruling coalition it could forge if it fell short.

Speaking to reporters at the Foreign Correspondents’ Club of Japan on Monday morning, Noda continued to give no indication as to when he’d make a final decision about a no-confidence motion.

“I get this question almost every day, and the answer is always the same: I’ll make a decision at the appropriate time, in the appropriate way, and after looking at the overall political situation,” he said.