TOKYO -- Japan's ruling party rushed to fill a power vacuum left by the resignation of Prime Minister Shinzo Abe, who was hospitalized Thursday for exhaustion but defended his snap decision to step down.
Despite plunging popularity ratings and a series of scandals in his Cabinet, Abe's announcement Wednesday that he would quit after one year in office caught even his ruling Liberal Democratic Party off guard.
A party meeting to vote on a successor was set for Sept. 23. Some officials wanted to hold the vote earlier, but it was put off to allow prospective candidates time to prepare.
Abe, diagnosed with abdominal problems caused by stress and fatigue, will continue to hold the post until his successor is named. But his hospitalization -- expected to last three or four days -- deepened the sense of confusion that his departure has fomented.
Ruling party officials said no acting prime minister would be named, with Chief Cabinet Secretary Kaoru Yosano taking over many of Abe's duties.
Former Foreign Minister Taro Aso was seen as Abe's most likely successor, but Finance Minister Fukushiro Nukaga also said he would seek the office. Former Cabinet spokesman Yasuo Fukuda was another expected contender.
"Some may perhaps call my decision irresponsible," Abe said in an e-mail posted after he was admitted to a Tokyo hospital. "However, I made up my mind that it would be in the very best interests of the nation, and of the people of Japan, for me to step down from my position."
Toshifumi Hibi, a senior doctor treating Abe, said he had gastrointestinal inflammation and had been put on an intravenous saline drip. "He is suffering from extreme exhaustion," Hibi said. "He has lost weight."
Though Abe did not cite his health as a reason for stepping down, Yosano said he had been checked regularly by his doctor since returning from a trip in August. Hibi said Abe had been taking medication to help him sleep.
"His doctor determined that his fatigue level has reached its peak, so I think that the doctor concluded that he needed to be examined at a well-equipped hospital," Yosano said.
The Liberal Democrats dominate the lower house of Parliament, and can thus name Abe's successor. No major policy changes were expected, as all candidates to replace Abe share his pro-U.S., fiscally conservative stance.
But Abe's meltdown was expected to have reverberations in upcoming parliamentary debates, and was likely to severely hinder the ruling party's ability to pass an extension of a bill allowing Japanese navy ships in the Indian Ocean to support U.S.-led coalition forces in Afghanistan.
Calls were also growing for whomever replaces Abe to dissolve the lower house for general elections.
"With the LDP government thrown into this much confusion, the voters should be asked in the proper fashion who their choice for leader is in a general election," the national Asahi newspaper said in an editorial. "That is the only way to bring back politics based on the people's trust."
Abe's support ratings in public opinion polls had sagged to about 30 percent, and he will leave behind a government known for scandals and gaffes. Four of his Cabinet ministers have resigned in scandals, including an agriculture minister who committed suicide over a money scandal.
"His political life is over," said Koichi Nakano, a political scientist at Sophia University. "This is unprecedented."
Nakano predicted the vote will focus on Aso. But he said Abe's predecessor, Junichiro Koizumi, could be called back.
"If an atmosphere is created in which the party needs a white knight, he may run," Nakano said. "When he first came out (in 2001), no one thought he would win and there weren't many supporters within the LDP. But he has charisma."
Koizumi has said he does not intend to run.