A total of 55.4 percent of respondents in a Kyodo News survey expressed opposition to the government's plan to lift Japan's self-imposed ban on exercising the right to collective self-defense, up from 48.1 percent the previous month.
In the nationwide telephone survey conducted on Saturday and Sunday, 57.7 percent also opposed the plan of Prime Minister Shinzo Abe's government to remove the long-standing ban by reinterpreting the pacifist Constitution instead of amending it, while 29.6 percent expressed support.
The survey also showed that 62.1 percent were concerned that the scope of Japan's exercise of collective self-defense would expand once the ban is removed, and 74.1 percent said the ruling coalition parties should not set a time frame to end discussions on the issue.
Abe is hoping to change the constitutional interpretation to enable the Self-Defense Forces to defend allies under armed attack in time for the planned revision by year-end of U.S.-Japan defense cooperation guidelines.
For decades, the government has maintained that Japan possesses the right to collective self-defense but cannot exercise it due to limits imposed by Article 9 of the Constitution, which forbids the use of force to settle international disputes.
In the survey, 34.5 percent said they support Japan exercising the right to collective self-defense, down from 39.0 percent the previous month.
The approval rating for Abe's Cabinet slipped to 52.1 percent, down 2.6 percentage points from the previous survey in May and the second-lowest level since his Cabinet was launched in December 2012.
On the economic front, 36.0 percent backed the planned consumption tax hike in October next year to 10 percent from 8 percent, while 59.7 percent were opposed, up 3.1 points from the previous survey.
As for nuclear plants, which remain offline following the 2011 Fukushima Daiichi nuclear crisis, 36.8 percent supported restarting them if their safety is confirmed, while 55.2 percent were opposed to reactivating them.
The survey showed a split on Pyongyang's agreement to reinvestigate the fate of Japanese nationals abducted by North Korea decades ago, with 47.3 percent saying the move is expected to lead to a settlement of the issue and 50.8 percent not expecting much from the probe.
The telephone survey covered 1,471 households with eligible voters, of whom 1,018 responded.