Japanese Prime Minister Shinzo Abe on Wednesday met a barrage of criticism about his government's handling of a controversial pension report as he faced off with opposition party leaders in a rare Diet debate ahead of an upper house election this summer.

In the first leaders' debate in parliament in a year, opposition party leaders took issue with the government's reluctance to address concerns about the reliability of the public pension system squarely, amid Japan's rapid graying population.

The pension issue has gathered attention since Finance Minister Taro Aso earlier this month refused to accept a report compiled by a Financial Services Agency panel. The panel estimated in the report that a retired couple would face a shortfall of 20 million yen ($184,000) if they live to be 95 years old under Japan's public pension system.

During the roughly 45-minute debate, Yukio Edano, leader of the main opposition Constitutional Democratic Party of Japan, said the government's refusal to accept the report raised questions about its seriousness in tackling the pension issue.

"Many voters are angry that even after the report came out the government is not responding to their worries that they cannot sustain their post-retirement life relying on pension benefits they are and will likely be receiving," Edano said.

Yuichiro Tamaki, head of the Democratic Party for the People, joined the chorus of criticism.

"The fact that the government is trying to treat the report as if it didn't exist or trying to hide what is inconvenient is raising public worries," Tamaki said.

((From R) Prime Minister Shinzo Abe, Yukio Edano, Yuichiro Tamaki, Kazuo Shii and Toranosuke Katayama.)

"People are thinking they have to save more and cutting back on spending...which I believe is the biggest bottleneck to 'Abenomics,'" he said, referring to Abe's economy-boosting program.

Japanese Communist Party chief Kazuo Shii and Japan Innovation Party co-head Toranosuke Katayama also raised the pension issue.

Abe, facing leaders from the four opposition parties, said he read the report but it was "misleading." He said the government has been reforming the pension system to make it sustainable and cater to the needs of various people living on pensions.

The report was intended to encourage Japanese people to better prepare for their post-retirement through proper management of financial assets beforehand, according to the panel.

The Abe administration is seeking to enhance social security for all generations, creating a society that supports people living to 100 years.

In 2017, the life expectancy of Japanese women was at 87.26 years and that for men at 81.09, according to government data. Debt-ridden Japan faces ballooning social security costs, accounting for about a third of its annual state budget.

During Abe's previous short stint as prime minister, his Liberal Democratic Party suffered a defeat in the upper house election in 2007 due in part to the mishandling of pension records.

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