A prolonged cycle of dashed hopes, failed strategies and policy deadlock -- Japanese politics is reminding some critics of the comedy film Groundhog Day, in which the hero repeatedly wakes to find he is living the same wintry day over and over.

But Prime Minister Yoshihiko Noda, now trying to crack that cycle and enact a tax rise to curb a huge public debt, might take heart from the 1993 film's happy ending, where the time-loop is broken by learning from past mistakes.

In 'Groundhog Day' the guy actually learns ... in the end, he gets it right, said Chuo University political science professor Steven Reed, adding that the electorate would be glad just to see an end to policy stalemate just wants to see some policy .

Support for Noda has dropped ... not because of what he did, but because he didn't do anything, he said.

If they (Noda's Democratic Party) raise taxes or do almost anything, they will win (the next election) overwhelmingly.

Noda, who took office last September as Japan's sixth premier in five years, is set to reshuffle his cabinet on Friday to replace two ministers censured by the opposition and remove at least one obstacle to passing bills in a divided parliament.

To underscore his commitment to tax reforms needed to fund the ballooning social welfare costs of a fast-ageing society, Noda also wants to draft staunch fiscal hawk Katsuya Okada, a past party leader, as his deputy, domestic media reports say.

The low-profile premier has promised to submit bills by March to double the sales tax in two stages by 2015, although doubts persist over whether changing the cabinet line-up will do much to win over opposition parties, who can use their control of parliament's upper house to block laws.

Noda has also faced down defectors from his own party and appears resigned to the possibility of more to come.

That tough stance could hold him in good stead with voters keen to see a strong leader in the mould of Junichiro Koizumi, who led his then-ruling Liberal Democrats to victory after party rebels blocked his pet project to privatise the postal system.

Noda is resigned to divisions in his party and knows his only hope is to forge ahead, said Atsuo Ito, an independent political analyst. He is ready to push for the sales tax rise even if it means destroying his administration. I think this will probably result in a general election (this year).

No lower house vote need be held until 2013, but speculation is already simmering that Noda could call a snap poll this year, either in exchange for opposition agreement to pass tax reform bills or in retaliation for their blocking the legislation.

To be sure, scepticism runs deep about the ability of Noda, a 54-year-old conservative who likened himself to a bottom-feeding loach fish when he took over, to succeed where his predecessors from either of Japan's two main parties failed.

GRAPPLING WITH GRIDLOCK

Japan's leaders have grappled with parliamentary gridlock since 2007, when the Democrats beat the then-ruling Liberal Democratic Party (LDP) and its partner in an upper house poll, creating a twisted parliament where an opposition-controlled upper chamber can block bills passed by the lower house.

Each new premier has been greeted with high voter ratings and hopes he can lead Japan out of its economic doldrums, only to see support slide as reform efforts are killed off and those in power stumble over gaffes and policy missteps.

I don't think anyone should put a lot of hope in Japanese politics. It would be nice to be pleasantly surprised, but it looks like it has sunk into a pattern, said Jeffrey Kingston, director of Asian studies at Temple University in Tokyo.

The upper house has too much power, so it is hard to get anything done unless you control both. That's a major reason why it is difficult to rule Japan.

Few expect the LDP to agree to serious talks on tax and social welfare reform, although the opposition party itself favours a sales tax hike and a recent media survey showed more than 40 percent of voters support the change, given public debt already twice the size of Japan's $5 trillion (3.26 trillion pound) economy.

Instead, analysts say the LDP is likely to attack the Democrats for failing to keep campaign promises to fund spending by slashing waste and rejigging the budget before raising taxes.

Create gridlock, stoke public frustration and the PM becomes the lighting-rod for frustration, Kingston said. From the LDP perspective, what's wrong with that picture?

Frustrated Japanese voters are hardly flocking to back the LDP in droves, having driven it from power more than two years ago after more than 50 years of almost non-stop rule.

But the party is pushing for a snap election in hopes it at least regain some of the seats lost in its crushing 2009 defeat and outperform the Democrats.

A Kyodo news agency poll published on Sunday showed that 22.4 percent of voters backed the LDP against 20.7 for the Democrats, the first time the LDP has had the lead since Noda took office.

Soggy ratings for the two big parties could provide a window of opportunity for a third force centred on the tiny Your Party, a band of small-government advocates -- especially if Noda fails to push tax reform through the lower house or stumbles in efforts to sell the painful prescription to voters.

If people believe the Democrats are not going to do anything, there will be a boom for the Your Party and Japan will become Italy, Chuo University's Reed said.

Pessimists who foresee little chance of success for Noda say Japan's only real chance of breaking the political deadlock may be a long-dreamt of reorganisation of the main political parties to create real choices for voters, since both big parties are internally split on everything from taxes to diplomacy.

The likelihood of a meaningful realignment, however, is questionable. There is no clarity on what policies would form the basis of political realignment, said Katsuhiko Nakamura, executive director of think tank Asian Forum Japan.

(Editing by Tomasz Janowski)