Outgoing Japanese Prime Minister Shigeru Ishiba’s ruling party opened official campaigning Monday to find a replacement who can restore political stability and voter support for the beleaguered Liberal Democrats.

Five candidates are vying for the party's top job ahead of a highly unpredictable vote in early October.

The race has a slogan: “Change, LDP.”

The winner must act quickly to address rising prices if the party is to have any chance of winning back support following devastating losses to both the LDP and its junior partner Komeito in the past year that deprived their coalition of a majority in either house of parliament.

Its new leader is still likely to be the prime minister because the LDP remains the top political party in Japan, while opposition groups are too splintered to form a coalition.

Whoever becomes the LDP leader must also gain cooperation from main opposition parties or risk facing constant no-confidence motions and a cycle of short-lived leadership.

The Oct. 4 vote is not open to the general public.

It is limited to 295 LDP parliamentarians and 1 million dues-paying grassroots party members.

That’s less than 1% of Japan's eligible voters.

The candidate who secures a majority becomes a party leader.

If nobody wins a majority, there will be a runoff between the top two candidates in the first round.

To be elected as prime minister, the new party leader will need votes from some opposition lawmakers in a parliamentary leadership vote, to be held within days.

All five candidates are incumbent and former Cabinet ministers.

They call themselves moderate conservatives as they emphasize their willingness to work with opposition groups.

Agriculture Minister Shinjiro Koizumi and former economic security minister Sanae Takaichi are considered the top contenders.

If elected, Takaichi, an ex-newscaster whose role model is former British Prime Minister Margaret Thatcher, will be Japan's first female prime minister.

The country ranks near the bottom internationally for gender equality, especially in politics.

Some experts worry that the hardline conservative would set back women’s advancement.

Others say her revisionist views of Japan's wartime history may complicate ties with Beijing and Seoul.

In a policy speech on Friday, Takaichi said she wants good ties with China, as an important neighbor and that her harsh comments about China are mostly related to economics.

AP video by Mayuko Ono