Japan's ruling Democratic Party of Japan and main opposition-led Liberal Democratic Party bloc agreeing in principle on a fresh deal on integrated tax and social security reforms based on hiking the nation's sales tax rate, has deepened a rapidly widening internal rift within the ruling party.

So polar are the views from supporters and opponents of Prime Minister Yoshihiko Noda's signature plan to double the nation's sales tax from within his own party that some ruling party lawmakers have indicated that the party could split over the issue of doubling the nation's sales tax to 10 percent by 2015, as the move negates some of the DPJ's election pledges and has irked a powerful coterie within the ruling party.

As the DPJ's integrity is being called further into question, the ruling LDP, political analysts attest, is maneuvering itself into a position to dragoon Noda into dissolving parliament and calling a snap election.

WIDENING RIFT

Noda has forged ahead with his plan to double Japan's sales tax stating recently that he absolutely intended to hold a vote on bills for integrated reform of the social security and tax systems on Thursday in Japan's more powerful lower house of parliament.

"June 21 is the end of the current Diet session, and my basic stance that the voting should be done by then on the day won't change," the Japanese leader was quoted as telling local media.

The opposition bloc, which includes the small New Komeito party along with the Liberal Democratic Party have, in principle, agreed on a number of revisions to the contentious reformatory bills and also hold Thursday as the deadline for the crucial vote, with both LDP President Sadakazu Tanigaki and New Komeito leader Natsuo Yamaguchi agreeing with Noda and other senior party executives that the vote should be held by Thursday.

But the three-way deal has drawn the wrath of a sizable anti- tax faction from within the DPJ, headed by ex-party chief Ichiro Ozawa, who believe that passing the tax bill with its new amendments will mean scrapping some of the party's key election policies, many drafted by Ozawa himself to see the DPJ swing into power in 2009, including publicly applauded pledges regarding minimum pension levels for retirees and free healthcare for the elderly.

"There is no way I can approve the amendments. They are completely denying our election manifesto," DPJ lawmaker Hiroshi Kawauchi told a local newspaper. "There is no need to hurry and hold a vote. We should hold thorough discussions on what is necessary for the people." he said

Kawauchi and more than 50 other Ozawa allies comprising the anti-tax faction within the DPJ are set to vote against the bills and with a 90-strong following of pro-Ozawa lawmakers in the lower house, a full revolt could seriously threaten the credibility of the DPJ and see its hold over the lower house start to go up in smoke.

"The point is not whether or not the bills will pass, we have to assume they will due to the number of supporters the DPJ has in the lower house, the point is the way it's been done. This has angered many DPJ lawmakers and not just the Ozawa loyalists," independent political analyst Teruhisa Muramatsu told Xinhua.

"There was no consensus reached within the DPJ on the new moves with the opposition and some DPJ lawmakers have publicly rebuked this style of autocratic browbeating," he said.

Indeed, Yukio Hatoyama, the DPJ's first prime minister after crushing the LDP in 2009, himself believes that the party could be on the brink of fracturing.

"If things are carried out forcibly, the party would split," Hatoyama told local reporters recently when quizzed on the issue earlier this week.

SNAP ELECTION LOOMS

Noda, facing reelection for his position as the DPJ's president in September, has on numerous occasions said that he would stake his political career on the line to push the tax hike bill through the current parliament session.

The prime minister believes that the move would be a key step in reigning in some of the nation's monumental public debt, which is currently the highest in the industrialized world at more than double the size of Japan's economy.

But while Noda has managed to curry enough favor from the opposition bloc for them to sign off on a new tax hike deal, the rift in his own party, widened further by top DPJ executives like policy chief Seiji Maehara opting not to prolong party discussions on the new cross-party accord and forge ahead with the vote before reaching a consensus, he has also put the party's integrity in serious jeopardy, according to some political analysts.

The LDP are becoming increasingly vociferous about the lack of unity in the ruling party and in a bid to head off a postponement of the vote in the eleventh hour, have threatened a no-confidence motion against the DPJ or a censure motion against Noda himself, according to opposition lawmakers.

But while the opposition bloc concedes that the nation's finances are in tatters and thus its in the best interests if the legislation is passed swiftly, in agreeing to do so they will almost certainly ensure Noda dissolves parliament for a snap election, although no lower house election is scheduled before the summer of 2013.

"At this stage it's almost inconceivable for the lower house not to be dissolved for a snap election," political commentator and Shizuoka-based author Philip McNeil told Xinhua. "The DPJ is, at best, rupturing from the inside out. The party has failed to live up to its manifesto, has seen its public support rate plummet and has essentially handed over all of its bargaining chips to the opposition bloc over the tax hike bill."

"Noda may well have staked his political career on doubling Japan's sales tax, but in doing so he's sacrificed his own party. Literally." McNeil said.

To this point, the LDP's deputy policy chief, Yoshimasa Hayashi, insisted the Japanese premiere call an election as the DPJ is seemingly in complete disarray and lost all credibility by not adhering to its original manifesto pledges.

"We will likely submit a no-confidence motion if the bills are enacted and they just try to close the parliament without a dissolution," Hayashi told local media.

Ozawa himself has described Noda's somewhat blinkered party leadership as a "sacrilegious betrayal" of the people and while the vote on Thursday may well go Noda's way, the bigger picture sees the the revolving door for Japan's mercurial leaders starting to spin once again.