(Bloomberg) -- Former Environment Minister Shinjiro Koizumi is leading in support from fellow lawmakers in Japan’s ruling party leadership race, polls showed, raising the possibility of him becoming the nation’s youngest prime minister.

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The 43-year-old Koizumi gained more than 50 of the 368 votes from lawmakers in the ruling Liberal Democratic Party, according to surveys by the Sankei and Mainichi newspapers published over the weekend. The leadership election for the conservative party is on Sept. 27 and the winner is almost certain to be elected as prime minister shortly after that due to the LDP’s dominance in parliament.

The race is one of the most wide open in the LDP’s history. The surveys said many lawmakers remain undecided or could still change their minds, indicating a fluid situation with just a few days to go until the vote, in which rank-and-file members will also cast ballots.

Takayuki Kobayashi, a former minister for economic security, and Yoshimasa Hayashi, the government’s top spokesman, followed closely with more than 40 votes each, the same polls showed. A Nikkei newspaper survey also placed the same three as frontrunners in lawmakers’ votes.

There are nine candidates running in the LDP leadership election and the vote is held among rank-and-file party members and LDP lawmakers, who get 368 votes each. If a candidate does not win a majority of the total votes, there will be a runoff between the top two vote-getters, in which almost all the votes are allocated to lawmakers.

Whoever wins the race will have a three-year term as head of the LDP and the victor may soon call a general election to serve as a mandate for the new government. Outgoing Prime Minister Fumio Kishida, who decided not to seek another term as leader, followed that path in 2021.

The Nikkei report said that two of three candidates, including Koizumi, former Defense Minister Shigeru Ishiba, who has emphasized regional revitalization, and Sanae Takaichi, a supporter of fiscal and monetary tools to stimulate the economy, are likely to be the main contenders for the two spots in the run-off election.

The LDP election is the first since a slush fund scandal that began last year rocked the party.

Takaichi, a minister for economic security, is trying to make history by becoming the first women to take the post of Japan’s prime minister. Ishiba remains popular among the rank-and-file.

Koizumi, the son of a former premier, is seeking to appeal to a younger generation of voters and refresh the image of the party. He has advocated for deregulation and labor market reform to give big businesses more flexibility in laying off workers — drawing criticism from other candidates.

If Koizumi wins, he may face trouble in keeping order in the LDP, which has established systems for leadership positions being held by its senior members. It has ruled Japan almost without interruption since its founding in the 1950s.

Candidates are scheduled to hold a series of policy debates over the next few days to appeal to undecided voters.

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