Long silent and out of the public eye, former Prime Minister Junichiro Koizumi’s recent rumblings against nuclear power are causing many to wonder if the most popular leader of recent decades is laying the groundwork for a political comeback.

The 74-year-old Koizumi has met separately with two opposition party heads — Tadatomo Yoshida of the Social Democratic Party and Yoshimi Watanabe of Your Party — to discuss his mission to rid the nation of all 50 of its nuclear reactors.

A visit to a spent-fuel disposal site in Finland following the 2011 Fukushima crisis converted him to an anti-nuclear activist, Koizumi claims.

Recent speeches given at closed-door meetings made the headlines of gossip magazines. Now Koizumi is stepping up his anti-nuclear campaign.

On Oct. 16, for the first time he allowed TV cameras from media outlets to shoot an anti-nuclear lecture in its entirety in Kisarazu, Chiba Prefecture.

Next up, Koizumi is scheduled to hold a news conference at the Japan National Press Club on Nov. 12, where he will face senior reporters from all the major news outlets for the first time since stepping down as prime minister in 2006.

“He has great power to send messages to the public. That’s what I felt today,” Yoshida of the SDP said after meeting Koizumi on Tuesday.

While serving as prime minister, Koizumi was often touted as a powerful communicator, a telegenic genius of the sound bite.

Critics called him a political agitator who labeled his foes “anti-reformers.” But his popularity with voters carried the Liberal Democratic Party to a landslide victory in the 2005 Lower House election, in part due to his quest to privatize the postal system.

In office, Koizumi rose above his party, a “lone wolf” who relied on communication skills to achieve his popularity. It is this approach, rather than by forming an alliance with a political force, that he appears to be adopting again to get his message across to the public.

During Tuesday’s meeting, Koizumi declined Yoshida’s offer to team up on the abolition of nuclear plants.

Instead, Koizumi stressed that each party and politician should make their own appeals to the public, and denied any intention to form a new political party, as gossip magazines have speculated, according to Yoshida.

It’s possible that Koizumi sized up the SDP and other anti-nuclear suitors and decided an alliance would not benefit him.

The SDP and Seikatsu no To (People’s Life Party) — the only parties to advocate for the immediate abolition of all nuclear plants — performed poorly in the latest Lower House election, in July, and their public support rates have remained below 1 percent all year, according to NHK polls.

Another hurdle to an alliance: The two share few views with Koizumi other than the anti-nuclear stance.

The SDP and Seikatsu no To support big government with increased spending on social security, while Koizumi was a champion of small government and free markets.

An advocate of pacifist policies, the SDP calls for cutting back U.S. military bases in Japan, while Koizumi was an earnest supporter of the Japan-U.S. security alliance.

“Nobody believes the SDP and Mr. Koizumi agree on (various policy issues.) They never agree on security issues, either,” LDP Secretary-General Shigeru Ishiba said Tuesday.

Still, officials at the prime minister’s office appear worried about Koizumi’s potential to sway the public.

Many LDP lawmakers have pushed long and hard for nuclear power plants to be built in their constituencies. And Prime Minister Shinzo Abe has pledged to restart any of the 50 reactors that pass Nuclear Regulation Authority safety tests.

At the end of last month, Abe’s Cabinet appointed Shinjiro Koizumi, a son of the former prime minister, as parliamentary secretary at the Reconstruction Agency.

This appointment was widely seen as an attempt to keep the young Koizumi, who is also popular with voters, under control, to prevent him from emerging, like his father, as a rising star of the anti-nuclear movement.

As a senior official at the Reconstruction Agency, the son is now obliged to toe the government line, including its energy policies.

On Wednesday, facing an opposition lawmaker during a Diet session for the first time, he was asked to explain his nuclear stance.

He simply responded that he would concentrate on urgent issues related to the wrecked Fukushima No. 1 nuclear plant, such as the problems of radioactive water and compensating local residents.

“I’m a parliamentary secretary and a member of the government,” he reportedly told the Diet session.