By Tetsushi Kajimoto and Tomasz Janowski
TOKYO (Reuters) - Japan's ruling Democrats on Tuesday delayed a final vote on their tax hike plan to deal with a no-confidence motion filed by fringe parties, exposing Prime Minister Yoshihiko Noda to more pressure from the opposition demanding an early election.
Elections are not due until August 2013 and Noda is reluctant to call a snap poll, in which the Democrats look certain to suffer a heavy defeat.
Initially the Democrats and their two main opposition rivals agreed to vote on the tax plan in the parliament's upper house on Wednesday and its passage appeared assured after the three parties backed the bill in a lower house vote in June.
The no-confidence motion filed by the small parties, which oppose the tax plan, is a symbolic gesture rather than a real threat, given that Democrats have enough votes to defeat the motion even if all opposition parties voted together.
But the delay will allow the main opposition Liberal Democratic Party (LDP) pile more pressure on Noda and seek his commitment to an early election, preferably this year, before backing the tax plan and his further political agenda.
LDP president Sadakazu Tanigaki told reporters on Monday: "If the bills are enacted, (Noda) needs to go to the people and set things right."
Asked if the LDP would also seek a no-confidence motion or censure motion unless Noda promises to dissolve parliament, Tanigaki said such arguments were gaining momentum in the party.
"If the bills are enacted, (Noda) needs to go to the people and set things right," he said.
Noda has staked his political future on his plan to double the sales tax to 10 percent by 2015, in an effort to curb Japan's snowballing public debt, splintering his party in the process. He has said he would risk his job to pass the bill.
The tax hike law would be a breakthrough for Japan, long trapped in a cycle of revolving-door governments and policy paralysis, and a personal victory for 55-year-old Noda.
But many lawmakers are wary of raising taxes ahead of a general election.
Despite backing Noda's tax plan, the LDP is mounting pressure on the prime minister to cut short his term.
The LDP is expected to revert to stalling tactics in the opposition-controlled upper house and block other legislation to force Noda to the ballot box. Noda has indicated he still wants to tick off more boxes on his to-do list before facing voters.
One is finalizing a new energy plan for the country after the previous one from 2010 -- which sought a greater role for nuclear power -- was scrapped after the 2011 Fukushima disaster.
Secondly, the government plans a supplementary budget, to keep the economy ticking over once the impact of reconstruction spending worth 3.6 percent of Japan's gross domestic product starts fading.
Finally, Noda will also need opposition votes to secure approval for a bill that authorizes the government to sell new bonds to finance the budget deficit.
Regardless of whether Noda succeeds with his agenda or when he calls an election, his Democrats appear destined to lose power just three years after they ousted the LDP. Noda's party rode a wave of public disillusionment after about 50 years of nearly non-stop LDP rule.
Now the Democrats face a similar backlash over broken promises, a confused response to last year's earthquake, tsunami and nuclear crisis as well as Noda's drift towards LDP policies on everything from taxes and the role of bureaucracy in policymaking to nuclear power and international diplomacy.
The latest poll by the Asahi newspaper showed support for Noda's government at a record low 22 percent and only 13 percent of those surveyed said they would vote for the Democrats if an election was called now.
According to the poll, the LDP could count on 23 percent, with 48 percent undecided, suggesting a wobbly coalition and more of policy gridlock as the most likely election outcome.
(Additional reporting by Sumio Ito and Shinji Kitamura; Editing by Michael Perry and Richard Borsuk)