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By Linda Sieg
TOKYO, Dec 8 (Reuters) - Voter support for Japanese Prime Minister Taro Aso's government slumped to about 20 percent in three polls published on Monday, further undermining his clout as he struggles with a fractious party and an economy in recession.
The surveys cast fresh doubt on Aso's ability to control policy decisions and keep his job, or even to prevent the long-ruling Liberal Democratic Party (LDP) from unravelling ahead of a general election that must be held by next September.
Aso is Japan's third premier in a row installed without an election.
"I think there will be more overt attempts to get rid of him, but given that they have done that three times without an election, the LDP is going to tear itself apart," said Koichi Nakano, a political science professor at Sophia University.
His predecessors, Shinzo Abe and Yasuo Fukuda, both quit after about a year in office after their support rates tumbled below 30 percent, a level seen by analysts as vital for survival.
The LDP tapped Aso in September in hopes he could win the ruling bloc a mandate to break through the political deadlock born of a divided parliament that is stalling policies as the recession deepens.
Instead, policy flip-flops and gaffes have eroded the 68-year-old Aso's popularity and prompted him to put off calling a snap election for parliament's powerful lower house.
Some analysts say the opposition Democratic Party - a mix of former LDP members, one-time socialists and conservative younger lawmakers -- has a good shot at taking power for the first time.
A survey by the Yomiuri newspaper showed Aso's support falling by about half to 21 percent, while the Mainichi newspaper showed a drop of 15 points to the same level. Another poll by the Asahi newspaper put his support at 22 percent.
"The people have completely given up on him," said Yukio Hatoyama, Secretary-General of main opposition Democratic Party.
With no obvious successors in the LDP to take Aso's place, some analysts said he could hang on until after the national budget for the year from April 1 is enacted in late March.
OPPOSITION DEMOCRATS BENEFIT
"If there were three or four candidates waiting in the wings, it is highly likely that Aso would resign and a new LDP leader take over," said independent political commentator Minoru Morita.
Aso's declining support has undermined his control over the long-ruling LDP, with many pushing for heftier spending to prop up the floundering economy despite huge public debt.
Others such as former financial services minister Yoshimi Watanabe are hinting at leaving to form new parties in hopes of bettering their chances in the looming election.
Another group could coalesce around former defence minister Yuriko Koike, who ran against Aso for the premiership under a reform banner, and her backer Hidenao Nakagawa, a former LDP secretary-general.
But Morita expressed scepticism over whether such manoeuvering would lead to the formation of new parties soon.
"They don't have the clout to set up new parties," he said.
Chief Cabinet Secretary Takeo Kawamura rejected calls for a change at the top.
"One should not change the horse when passing through a strong current, and we are not in a situation where we can change horses. I think it is a crucial time for the ruling coalition to bond and work together," he told reporters.
The surveys also showed the Democrats taking a clear lead among voters when they were asked for whom they would cast their ballots in the next election.
Forty percent of voters in the Yomiuri poll opted for the Democrats while only 24 percent chose the LDP.
Democratic Party leader Ichiro Ozawa, a former LDP heavyweight who bolted the party in 1993 and helped briefly oust it from power, has also gained from Aso's decline.
Ozawa, 66, suffers from an autocratic image and has lagged Aso in polls, but he led in all three new surveys when voters were asked which of them was most suitable to run the country.
Still, many voters appear dissatisfied with both main parties, whose squabbling in a divided parliament is making it hard to implement policies as the economy stumbles.
Nearly 60 percent of voters in the Yomiuri want said they wanted a rejig of political parties after the election or a "grand coalition" between LDP and the Democrats.
The Yomiuri survey was conducted over the phone on Friday, Saturday and Sunday, while the Mainichi and Asahi surveys were conducted over the phone on the weekend. (Additional reporting by Yoko Kubota)