Prime Minister Shinzo Abe's party looks set for a huge win on Sunday in a low-voltage election that will allow the conservative leader to claim a fresh mandate for his reflationary policies to revive Japan's long-stagnant economy.
Voting began at 7 a.m. (2200 GMT) for an election that the premier has cast as a referendum on his "Abenomics" strategy to end deflation and generate growth. Media exit polls, which have proved reliable in the past, will come out at 8 p.m. (1100 GMT).
Mr. Abe called the vote after just two years in office in a gamble originally seen as potentially costing his party seats. But media projections have said his long-dominant Liberal Democratic Party (LDP) could win more than 300 seats in the 475-member lower house, possibly its biggest victory since its founding nearly six decades ago.
Together, the LDP and its junior partner are forecast to keep their two-thirds "super-majority", ensuring the smooth operation of parliamentary business.
Experts cautioned, however, that any mandate for Abe might be smaller than first appeared since disaffected voters who are increasingly dubious of Abenomics but wary of the opposition could stay home in large numbers.
"This is not so much a vote of confidence in Mr. Abe and the LDP as a vote of no-confidence in the political opposition," said Columbia University professor Gerry Curtis.
Mr. Abe returned to power for a rare second term as premier in 2012 pledging to reboot Japan's economy, plagued by deflation and an ageing, shrinking population.
But hopes for his "Three Arrows" of hyper-easy monetary policy, government spending and reforms such as deregulation were tarnished after the economy slipped into recession in the third quarter following an April sales tax rise. Recent data suggest any rebound is fragile.
Mr. Abe decided last month to put off a second tax hike to 10 percent until April 2017, raising concerns about how Japan will curb its huge public debt, the worst among advanced nations.
But media forecasts suggest the main opposition Democratic Party of Japan (DPJ) has been unable to gain traction, largely due to voters' memories of a 2009-2012 rule plagued by policy flip-flops, infighting and three premiers in three years.
Long-term leader?
Mr. Abe, under the slogan "This is the only path", called the election in a bid to strengthen his grip on power before tackling unpopular policies, such as restarting nuclear reactors taken off-line after the 2011 Fukushima disaster and a security policy shift away from post-war pacifism.
The expected LDP victory could make it easier for Mr. Abe to be re-elected in a party leadership race next September, boosting the chance he stays in power through 2018 and becomes one of Japan's rare long-term leaders.
Aside from local elections in April, his coalition will probably not need to face voters until a 2016 election for the upper house, where the LDP and the Komeito party now hold a majority.
"If Abe wins big, he will at least have a free hand on policy until the 2016 upper house election. The ability of the administration to get policy through will increase a lot," said Hideyuki Ishiguro, senior strategist at Okasan Securities.
Doubts, however, persist over whether Mr. Abe will now knuckle down on his "third arrow" of reforms in politically sensitive areas such as labour market deregulation that would make it easier to shift workers to growth areas but also to lay off employees, and reform of the highly protected farm sector.
Critics say progress has been limited so far, partly due to opposition from members of Abe's own party.
"My personal assessment is that we are likely to see more of what we've seen - piecemeal reforms moving more or less in the right direction, but at a fairly slow clip and no bold breakthroughs because of this election," Mr. Curtis said.
Some experts say Mr. Abe could also turn attention away from the economy to his conservative agenda that includes laying the groundwork to revise the post-war, pacifist constitution and recasting Japan's wartime past with a less apologetic tone.
That agenda raises hackles in China and South Korea, where bitter memories of Japan's past militarism run deep.
"If Abe forgets about economic policies and looks at self defence and constitutional reform, this will be a big negative for the market," said Makoto Kikuchi, CEO of Myojo Asset Management.
The LDP had 295 seats and Komeito 31 in the 480-member lower house when it was dissolved for the snap election. The DPJ had 62 seats heading into the poll. Five seats were cut through electoral reform.
