Junichiro Koizumi, known as a firm opponent of nuclear power following the 2011 Fukushima triple meltdown, on Wednesday criticized Prime Minister Shinzo Abe's policy to revive the country's fleet of idled nuclear reactors.

"The government says Japan has the world's toughest safety standards for nuclear plants, but are they really tough compared with (regulations in) the United States, France or Finland? Not at all," Koizumi, who served as prime minister from 2001 to 2006, told a symposium in Tokyo.

All 48 commercial reactors in Japan are currently offline, but Abe is pushing for the restart of reactors that have cleared the post-Fukushima regulations. A two-reactor plant operated by Kyushu Electric Power Co. may go back online as early as the beginning of the next year.

Koizumi urged Abe to break away from nuclear power, saying "People would not cooperate" over the matter of finding a final disposal site for high-level radioactive waste unless the government vows "not to increase nuclear waste any more."

In May, Koizumi established a body to promote renewable energy together with another former prime minister, Morihiro Hosokawa, who unsuccessfully ran in the Tokyo gubernatorial election in February on an anti-nuclear platform.