Japanese Prime Minister Shinzo Abe was forced to reprimand his defense minister over a gaffe on Monday, as his cabinet's support rates slid below the critical 30 per cent level in a poll weeks before an upper house election.
Government mismanagement of pension records and voter concern about political corruption have left Abe struggling to win back support ahead of the July 29 election.
He was dealt a fresh blow on Saturday when Defense Minister Kyuma sparked public anger by saying he thought the US atomic bomb attacks on the cities of Hiroshima and Nagasaki at the end of World World Two "could not be helped."
Kyuma apologized on Sunday, but opposition lawmakers called for his resignation after the latest in a series of gaffes.
Abe urged Kyuma to "take strict care with his remarks," the defense minister told reporters after the two held a meeting at he prime minister's official residence on Monday.
The blunder comes at a bad time for Abe. Only 28 per cent of those who responded to a weekend Asahi newspaper poll said they supported him, down from 31 per cent in the previous survey a week earlier and the weakest result for the once popular leader since he came to office last September.
Some 48 per cent of respondents to the survey said they did not support the prime minister.
A separate poll published by Jiji news agency in June put Abe's support at 28.8 per cent -- the first time a Japanese prime minister's support rate had fallen below 30 per cent since 2001.
The gaffe-prone prime minister at that time, Yoshiro Mori, was swiftly replaced to improve the ruling Liberal Democratic Party's chances in an upper house election that year.
A poll in the Mainichi Shimbun also published on Monday showed support for Abe at 32 per cent, while 52 per cent of respondents said they did not support him, the highest percentage recorded during his premiership.
Almost two-thirds of respondents to the Mainichi poll said they were not happy with Abe's efforts to clear up the chaos in the pensions system after the government lost track of millions of premium payments, sparking public anxiety.
The issue dominated a debate on Sunday between Abe and Ichiro Ozawa, leader of the main opposition Democratic Party.
Despite Abe's woes, however, the Democrats have not pulled far ahead in opinion surveys. In the Asahi poll, 25 per cent of respondents said they would vote for the Democrats in the proportional representation section of the two-part election, while 19 per cent said they would vote for the LDP. In the prefectural district section of the election, 26 per cent said they would opt for the LDP and 25 per cent for the Democrats.
Abe would not automatically have to step down if his LDP-led coalition loses its majority in the upper house, and the ruling camp might be able to woo independent lawmakers or members of a small conservative party to keep its grip on the chamber.
But a big loss would mean the ruling bloc could not enact legislation, which must be approved by both houses of parliament, threatening political paralysis and sparking calls for Abe to quit or even call a snap lower house election.