TOKYO — For the second time in a year, a struggling Japanese prime minister has unexpectedly quit, leaving the country politically adrift as it struggles to deal with a deadlocked parliament and worsening economy.
Yasuo Fukuda, 72, appeared to blindside his party Monday, saying he would resign as soon as a new leader was picked. He blamed what he saw as an obstructionist opposition party for his departure, but offered no clear explanation for his timing.
"I have decided to step down so as not to create a political vacuum," he told a hastily called news conference.
Many here argue that the country is already facing a vacuum in political leadership. With opposition parties controlling Japan's upper house and pressing for an election, a frustrated Fukuda was unable to pass major legislation, including a bill essential to renewing the participation of Japan's navy in American-led anti-terrorism activities in the Indian Ocean.
Fukuda was further damaged by a weakening economy, which has seen negative growth while prices jumped, especially for food. An $18-billion stimulus package introduced last week had been dismissed by most market analysts as ineffectual.
The combination of economic trouble and the governing Liberal Democratic Party's apparent drift sent its approval rates plummeting in the last month to below 30% in most polls.
The LDP reached out to Fukuda just a year ago after Shinzo Abe, his much-heralded predecessor, threw in the towel after a year of dismal leadership. Abe left his party in tatters, foundering on a conservative agenda to restore national pride and core Japanese values, dismissed as out of touch by voters more worried about their economic future.
They delivered that message during elections for the upper house in 2007, in which they handed control to the opposition Democratic Party of Japan.
After the erratic Abe, Fukuda was regarded by the party as a steady replacement who could steer the government through the legislative roadblocks. But the opposition never allowed him to get traction, blocking almost every major initiative in hopes of forcing a general election the LDP does not want. The dim electoral prospects had also unsettled the New Komeito Party, a powerful grass-roots machine built on a national Buddhist organization, whose lawmakers are essential to keeping the LDP in power.
"The LDP would have no chance of winning an election if it was called now," said Minoru Morita, a leading political analyst.
"Nothing worked for Fukuda. He must have realized the party could not win under his leadership."
The despairing mood inside the LDP had increased pressure on Fukuda to give way before the next election to Taro Aso, the party's secretary- general, or No. 2 politician. Aso is widely expected to win the leadership now, though he may be challenged by a small field including former Defense Minister Yuriko Koike.
The feisty Aso is a former foreign minister with a strong nationalist streak, whose open embrace of Japanese pop culture, such as manga (comics), made him a somewhat quirky politician within the staid LDP. He has tried and failed to win the LDP leadership three times, most recently last year when party elders -- if not all its foot soldiers -- moved to Fukuda in search of calm after the tempests of the brief Abe era.
After his last defeat, Aso took a hiatus from government posts, traveling the country to build a wider base of support. In the course of the sabbatical he appeared to break with his previous emphasis on traditional values to take into account the bread-and-butter concerns facing most Japanese.
He published two magazine articles widely seen as political mission statements, acknowledging that the nationalist passions of the Abe government of which he had been a senior member had blinded it to the bigger economic problems.
Aso now argues for radical economic measures to fix Japan's long-term problems, most notably an increase in the consumption tax to 10% to better fund a shaky pension system that faces an aging population and shrinking work force.
Raising the consumption tax has always spooked Japanese politicians, including the reform-minded Junichiro Koizumi, the last popular prime minister. Even Koizumi saw the tax hike as one ambition too far.
But Aso's bold embrace of higher taxes and radical reforms conjures memories of Koizumi's political style: breaking with the inherent caution and stagnation of the ruling party power brokers by going over their heads to appeal to voters.
"Aso will be a hybrid," said analyst Hirotaka Futatsuki. "He is a typical old-style LDP politician at heart. But in order to be popular he has to take the Koizumi-style approach."
He may not have much time. The opposition drumbeat calling for an election has already picked up the tempo after Fukuda's resignation. Voters may be equally restless: Koizumi was the last LDP leader to win an election. The next prime minister will be the third to emerge from the LDP backrooms to run the country without going to the public for a mandate.
Ueno reported from Tokyo and Wallace from Los Angeles. Special correspondent Naoko Nishiwaki contributed to this report.