TOKYO - An extraordinary parliamentary session that convened Monday may put a spotlight on a rule that could lead Prime Minister Sanae Takaichi's government to push through key legislation without being stalled by prolonged deliberations in the Senate, where her ruling bloc remains a minority.
Under the rule, if the less powerful upper chamber fails to hold a vote for 60 days after receiving a bill that has been passed by the House of Representatives, it can be deemed to have rejected the legislation, allowing the lower house to override it with a two-thirds majority.
During the 69-day session through Dec. 12, the government aims to enact legislation on two major initiatives that would face opposition resistance -- a consumption tax cut on food products and a reduction in the number of seats in the lower house.
While the bar for invoking the rule seems high due to the risk of drawing criticism from opposition parties and the public over the radical measure and a tight timeline, political experts say the mere likelihood of applying the 60-day rule could put pressure on opposition parties.
"Of course, the ruling coalition will proceed with deliberations on key legislation with the 60-day rule in mind," said Kazuhiko Ozawa, a political science professor at J.F. Oberlin University.
The ruling camp of Takaichi's Liberal Democratic Party and its junior partner, the Japan Innovation Party, holds a combined 351 of the lower house's 465 seats as a result of a general election in February.
For the rule to be invoked before the scheduled end of the session, in the absence of an extension being agreed, a bill would likely need to clear the lower house by around mid-October.
At a press conference last week, Masaji Matsuyama, chairman of the LDP members' general assembly in the Senate, said that resorting to the 60-day rule during the extra session is "completely out of the question," stressing the importance of "proper management of Diet affairs."
The most closely watched bills in the session are those related to the government's plan to lower the consumption tax rate on food and beverages from 8 percent to 1 percent for two years from April to ease the burden on households from prolonged inflation.
The proposal has faced backlash from opposition parties that cited its lack of immediate effect, among other reasons, although reducing or abolishing the consumption tax was a major campaign pledge not only of the ruling bloc but of most opposition forces in February's election.
Meanwhile, Ozawa said some LDP members, along with the opposition camp, "could unexpectedly oppose" the bill to downsize the lower house, and the ruling parties "may have no choice but to bet on a two-thirds majority" to supersede the upper chamber's decision.
The JIP has long advocated reducing lawmaker seats, calling the seat-cut bill a "prerequisite" in coalition talks with the LDP. The two conservative parties signed an agreement in October 2025, which played a major role in Takaichi's rise to the premiership that month.
Against this backdrop, Ozawa said the ruling bloc may pursue early passage of the seat-reduction bill to secure 60 days' leeway before the session ends.
Nozomu Yamazaki, a Chuo University professor, said the 69-day session appears to have been set in part to preserve the 60-day rule as a "last resort" and give the government an advantage in negotiations with opposition parties.
"The problem is that the government might shorten deliberations in the lower house" after taking account of the target date for enactment, Yamazaki said, adding, "Whether sufficient debate would have taken place is a separate issue" even if key legislation is enacted by the lower house's supermajority in a second vote.
He also said that overriding the upper house's objection to bills under the 60-day rule could "damage trust with opposition parties and make future policy cooperation more difficult."
Within the LDP, some senior members such as Secretary General Shunichi Suzuki have called for the major opposition Democratic Party for the People, which has a relatively similar policy stance, to join the coalition government.
But Yamazaki said that what is more important is that "opportunities to examine problems with bills and amend them would be lost," while also mentioning the possibility that the session could be extended for the use of the 60-day rule.
Yamazaki said it cannot be justified "to use the urgency of providing support for people's livelihoods as a reason to skip deliberations, or to push through changes to the electoral system in order to maintain the coalition."
Ryota Murai, a political science professor at Komazawa University, said that the lower house overriding the Senate's decision is a procedure permitted under the Constitution, but efforts should first be made to secure majority support in the upper house.
"The Diet is not simply a place to count numbers," Murai said. "It is a place where the ruling and opposition parties explore desirable policies together and the government's views are disclosed."
