* LDP, ally could win 300-plus seats in 480-seat parliament
* Opposition Abe's coalition could get key 2/3 majority-poll
* BOJ may ease monetary policy next week, sources (Adds quotes, colour from campaign trail)
By Kaori Kaneko and Antoni Slodkowski
TOKYO/TAKATSUKI, Dec 11 (Reuters) - Conservative former Prime Minister Shinzo Abe's opposition Liberal Democratic Party (LDP) and its smaller ally are heading for a resounding victory in Sunday's election, winning more than 300 seats in parliament's 480-member lower house, media surveys showed on Tuesday.
Abe, 58, who resigned abruptly as premier in 2007 after a troubled year in office, is pushing the Bank of Japan (BOJ) for more powerful monetary stimulus and promises to boost public works to rev up a stagnant economy.
Abe, the grandson of a wartime cabinet minister who became prime minister after World War Two, also favours a tough stance against China in a territorial row and loosening the limits of Japan's 65-year-old pacifist constitution on the military.
Prime Minister Yoshihiko Noda's Democratic Party of Japan (DPJ), which surged to power in 2009 for the first time, could get fewer than 80 seats at the election, the papers said.
The conservative Sankei, whose poll was based on a smaller sample, said an LDP-New Komeito party coalition could even win the two-thirds majority needed to over-ride the upper house, where no party has a majority and which can block legislation.
That could potentially break the political deadlock that has plagued successive governments since 2007. But the paper warned that almost 40 percent of those surveyed had not decided how to vote.
Many voters have become disillusioned with the ruling Democrats who promised to break the "iron triangle" of cosy ties between big business, bureaucrats and lawmakers, nurtured during the LDP's nearly unbroken half a century rule.
But while voters are returning to the long-dominant LDP, there is little tangible enthusiasm for Japan's main opposition.
"I feel betrayed by the DPJ which promised to change so much, but achieved so little. They came across as immature, disorganised and ineffective," said Junko Makita, 59, a housewife in Takatsuki, a city of 360,000 just outside western metropolis of Osaka.
"That said, I'm not putting my hopes up too high for the LDP either, but at least they are more experienced," she said.
Takatsuki is a microcosm of Japan's fragmented politics, where a DPJ incumbent is fighting a losing battle against a well known local doctor on the LDP's list and a young candidate from the right-leaning Japan Restoration Party.
The area is the power base for the Japan Restoration Party, founded by outspoken Osaka mayor Toru Hashimoto, and polls suggest it could capture as many as 50 seats after it joined forces with an octogenarian nationalist Shintaro Ishihara.
A solid LDP-New Komeito lower house majority would make any formal coalition with the new Restoration party less likely, but a strong result could make it a force to contend with in future.
BANK OF JAPAN UNDER PRESSURE
Reviving Asia's second largest economy, which is slipping into its fourth recession since 2000, is a major election issue and has seen hawkish Abe pressure the BOJ for "unlimited" easing to achieve a 2 percent inflation, double the bank's target.
"I'm graduating next year, so I want politicians to boost our economy, particularly companies like Panasonic or Sharp which are in a very bad shape," said Takashi Nishida, 21, electronics student at Kyoto's Ritsumeikan University.
Japan's central bank will likely ease monetary policy next week, sources say, as looming risks such as the potential fallout from the U.S. fiscal cliff and weak Chinese growth cloud the outlook for an economy already seen as in recession.
The most likely option is for the central bank to expand its asset-buying and lending programme, currently at 91 trillion yen ($1.1 trillion), by another 5-10 trillion yen, at the meeting on Dec. 19-20, sources familiar with its thinking have said.
For now, many in the central bank want to hold off on any new initiatives unless the U.S. Federal Reserve, which holds its policy-setting meeting this week, surprises markets with a bigger-than-expected stimulus and triggers a sharp yen rise.
Abe has also tapped a nationalist sentiment in Japan to win voters and has promised to get tougher with Beijing in a territorial row and to loosen the pacifist constitution.
The Philippines said on Monday that a stronger Japan would act as a counterbalance to the military rise of China, something that is worrying smaller Asian nations as territorial disputes heat up in the region.
Right-leaning parties' tough talk resonates with many voters, after a simmering dispute with China over a chain of East China Sea islets flared up earlier this year, culminating in anti-Japanese protests and boycotts of Japanese products.
"The most important thing is to show that Japan has its voice, show to the world what is our stance" said Isao Habe, 56, a manager at an electronics maker in Takatsuki, who plans to vote for the LDP candidate.
"I want the government to be more assertive."
Revising the pacifist constitution would require a two-thirds majority in both houses as well as a majority in a public referendum, but changes to how it is interpreted are easier to accomplish. (Writing by Linda Sieg; Editing by Tomasz Janowski)