TOKYO, Sept. 2 (Xinhua) -- Japan's ruling Liberal Democratic Party (LDP) on Wednesday decided to hold a presidential election on Sept. 14 to pick Prime Minister Shinzo Abe's successor.

The race for the party's top position will officially start at 10 a.m. local time on Sept. 8, party officials said.

The party's new leader will be elected at a joint plenary meeting of LDP party members from both houses of Japan's bicameral parliament at a Tokyo hotel from 2 p.m. local time on Sept. 14, the officials added.

The LDP and the main opposition Constitutional Democratic Party of Japan (CDPJ) have agreed to convene an extraordinary Diet session and choose the new prime minister on Sept. 16.

The winner of the LDP's presidential race who is all but certain to become the newly-elected prime minister due to the LDP's majority in parliament, will serve the remainder of Abe's term as the president of the party through September 2021.

The LDP's General Council, however, has decided to hold a scaled-down presidential election with voting applicable only to lawmakers and delegates from the party's local chapters.

The abridged election process was decided by the council to simplify the process and to avoid a political vacuum as Abe abruptly stepped down midterm due to health issues.

In the scaled-down vote, 394 Diet members will cast ballots and a total of 141 votes will be cast by three delegates each from the country's 47 prefectural chapters.

The choice to hold a scaled down election has drawn flak from some candidates and lawmakers, however.

The LDP's former Secretary-General, Shigeru Ishiba, who is popular with rank-and-file members and the public, but has been a vocal critic of Abe, and was the only contender in the previous LDP leadership race in 2018, described the council's decision against an open election as "regrettable."

"It is extremely regrettable that not all party members can vote this round," Ishiba said at a press conference as he formally announced his candidacy on Tuesday.

Ishiba's concerns have been echoed by more than 140 lawmakers at the time who have signed a petition calling for an open election.

"It's important that rank-and-file members vote, so that the new leader takes over the reins of government after Abe with a strong mandate," Ishiba said, adding that despite the council's decision, he would not give up.

Other LDP heavyweights have also thrown their hats in the ring to take over the LDP's top post, with LDP policy chief and former Foreign Minister Fumio Kishida also announcing his candidacy on Tuesday.

Kishida, who didn't stand in the party's previous election so as to support Abe, said he wants to be "a leader who can gain the cooperation of the people."

"While regarding highly the fruit of the Abe administration, we must work on new issues that arise with as times change," Kishida said, with reference to issues of earning imbalances and the need to tackle the spread of the novel coronavirus while balancing economic issues.

"For the Japanese people and for my country, I am willing to do everything needed. I would like to ask for your support," Kishida said.

Yoshihide Suga, who has been Chief Cabinet Secretary for nearly eight years and considered as a "continuity candidate," formally declared his candidacy at a press conference Wednesday evening.

Suga, Japan's top government spokesperson who has been one of Abe's closest confidants for almost eight years, said that he would continue the prime minister's "Abenomics" economic policy mix were he to win the race.

Suga has the backing of at least four of the LDP's seven factions, including Abe's, the party's largest led by former Secretary-General Hiroyuki Hosoda.

Suga has likely already secured support from more than two-thirds of the party's lawmakers, local media reported.

Defense Minister Taro Kono has said he will not run in the race after discussions with his camp. Kono belongs to Finance Minister Taro Aso's faction which will back Suga.

Environment Minister Shinjiro Koizumi has also said he will not enter the leadership race.