A group advised by former Prime Minister Junichiro Koizumi on Wednesday unveiled details about a bill calling for an “immediate halt” to Japan’s reliance on nuclear power to prevent a recurrence of the 2011 Fukushima disaster. The group is seeking to submit the bill to an upcoming Diet session in cooperation with opposition parties.

Sporting his signature leonine hairdo, Koizumi, one of Japan’s most popular prime ministers in recent memory, made a rare appearance before reporters with his unabated frankness, lashing out at Prime Minister Shinzo Abe over his persistent pro-nuclear stance.

“You may think the goal of zero nuclear power is hard to achieve, but it’s not,” Koizumi said, adding that he believes many lawmakers of the ruling Liberal Democratic Party support nuclear power passively out of respect for Abe, but that they could be persuaded to embrace a zero-nuclear policy under a different leader.

“Judging from his past remarks, I don’t think we can realize zero nuclear power as long as Abe remains in power. But I do think we can make it happen if he is replaced by a prime minister willing to listen to the public,” Koizumi told a packed news conference organized by Genjiren, an anti-nuclear association for which he serves as an adviser along with Morihiro Hosokawa, another former prime minister.

Claiming that the March 2011 triple meltdown at the Fukushima No. 1 nuclear power plant exposed the “extremely dangerous” and “costly” nature of atomic power — with a means of disposing of spent fuel still not in sight — the bill drafted by Genjiren calls for Japan’s “complete switch” to renewable energy.

Specifically, it demands that all active nuclear reactors be switched offline immediately and that those currently idle never be reactivated. It also defines the government’s responsibility to initiate steps toward a mass decommissioning and to map out “foolproof and safe” plans to dispose of spent fuel rods.

The bill sets forth specific numerical targets, too, saying various sources of natural energy, including solar, wind, water and geothermal heat, should occupy more than 50 percent of the nation’s total power supply by 2030 and 100 percent by 2050.

That Japan has experienced no mass power shortage following the shutdown of all 48 reactors in the wake of the 2011 crisis, except for a handful since reactivated, is in itself a testament to the fact that “we can get by without nuclear power,” Koizumi said.

A 2017 white paper by the Ministry of Economy, Trade and Industry shows Japan’s reliance on nuclear power has plunged to a mere 1 percent after the Fukushima meltdowns. The vast majority of Japan’s power is supplied by sources such as liquefied natural gas, coal and oil.

Although the controversy over nuclear power has rarely emerged as a priority in recent parliamentary debates, the creation of the main opposition Constitutional Democratic Party of Japan may herald a breakthrough.

Later Wednesday, Genjiren pitched the bill to the CDP in a meeting with some of its members, including former Prime Minister Naoto Kan, who was in power when the Fukushima crisis erupted.

The CDP seeks to submit its own “zero nuclear power” bill to a regular Diet session slated to kick off later this month, positioning itself as a clearer anti-nuclear alternative to Abe’s ruling party than its predecessor, the Democratic Party.

The DP, which until recently held the most seats among opposition parties in both houses of the Diet, had failed to go all-out in crusading against nuclear power under the previous leadership of Renho, who goes by only one name.

At a party convention last March, Renho balked at adopting an ambitious target of slashing Japan’s reliance on nuclear power to zero by 2030 after reportedly facing resistance from party members beholden to the support of electricity industry unions.

In a preliminary draft unveiled Wednesday, the CDP’s bill-in-the-making called for ridding Japan of nuclear power “as soon as possible.”