Since the ruling Liberal Democratic Party lost its Upper House majority in an election on July 20, opinion polls have shown farm minister Shinjiro Koizumi emerging as the top pick for the “next prime minister” among both supporters of the party and unaffiliated voters.

Koizumi is also popular within the party, having thrown his support behind various candidates by traveling nationwide to speak at their public rallies. He is a respected figure in the LDP’s youth bureau, which he chaired between 2011 and 2013. As a legacy lawmaker, the son of former Prime Minister Junichiro Koizumi has used his influence to speak on behalf of party rookies.

Amid calls to oust Prime Minister Shigeru Ishiba, however, the younger Koizumi has dodged questions about his boss, who is also LDP president, unlike other lawmakers who have openly demanded his resignation.

On Wednesday, Koizumi said that it is “too early” to say how he will respond to the LDP presidential election committee’s upcoming canvassing of sitting parliamentarians and prefectural chapters on whether to hold a leadership vote.

Koizumi even thanked Ishiba, who was farm minister in 2008, for being “more understanding and supportive than anyone” of the challenge he faces as he attempts to solve Japan’s rice woes.

“If it hadn’t been for the prime minister’s direct support, I couldn’t have rolled out such a major policy. I’m truly grateful,” he said, referring to Ishiba’s decision to boost Japan’s rice production to tamp down soaring prices.

Officially, Ishiba cited Koizumi’s experience chairing LDP committees on marine products and forestry as the reason he named him farm minister in May, following predecessor Taku Eto’s resignation over a rice gaffe.

Locking Koizumi into the Cabinet is Ishiba’s way of holding him “hostage” — turning a potential rival into a team player, at least for now, according to one expert.

“The anti-Ishiba lawmakers can’t take Koizumi. So, Ishiba’s been doing pretty well. This is the scenario Ishiba imagined when he made Koizumi farm minister. When push comes to shove, Koizumi can’t be pulled away,” said Ritsumeikan University political scientist Masato Kamikubo.

In a Jiji Press poll last week that asked respondents who among 14 lawmakers they thought was suited to become the next prime minister, Koizumi was the second pick overall, behind former economic security minister Sanae Takaichi. But among unaffiliated voters — who made up half of all respondents — Koizumi came out on top, with 15.6% of their support, followed by Takaichi at 12.8% and Ishiba at 7.6%.

In a Nikkei poll published July 28, Koizumi and Takaichi were tied at 20% support among all survey takers, which consisted of supporters of various parties and voters without party allegiances. Koizumi, however, had the highest number of votes among LDP supporters and unaffiliated voters.

However, with Koizumi stuck in Ishiba’s chokehold, his fans can’t rally around him.

When pressed on whether a presidential election is necessary, whether he plans to support Ishiba until the end and whether he would run for president, Koizumi always steered the conversation back to his “ministerial responsibilities.”

“Koizumi is a hostage. Ishiba captured him,” added Kamikubo.

“Koizumi is popular, especially among the young lawmakers. But on the flip side, without Koizumi, the young won’t get together.”