Voting began Sunday morning in Japan's upper house election, the first national election since Prime Minister Shinzo Abe formed his cabinet in September.

Voting started at 7:00 a.m. (2200 GMT, Saturday) across Japan and ends at 8:00 p.m. (1100 GMT) in most stations.

The election for half the seats in parliament's 242-member upper house comes just 10 months after Abe, 52, took over and pledged to bolster Japan's global security profile, rewrite its U.S.-drafted constitution and nurture economic growth.

According to recent media surveys, Abe's ruling Liberal Democratic Party (LDP) is fighting an uphill battle to maintain majority, while major opposition Democratic Party of Japan seems to have gathered momentum to fight for the controlling power in the House of Councilors.

Half of the seats in the upper chamber are up for grabs every three years in Japan. A total of 377 candidates are contesting for 121 seats at stake this time.

Of the 121 seats, 73 are from single- or multi-seat prefectural constituencies and the rest 48 are from the national proportional representation block.

Before Sunday's election, the ruling coalition of the LDP and the New Komeito party jointly held 133 seats. Of the total, 57 seats and another of a pro-LDP independent are uncontested this time. Thus the two parties need to secure at least 64 seats to control the upper house.

According to the ministry of internal affairs, some 8.82 million absentee ballots have been cast as of Friday. The number of eligible voters in Japan stands at around 104 million.

As the ruling coalition has a commanding majority in the lower house of the parliament, a failure to maintain majority in the upper house would not immediately reverse the political picture. However, losing the battle would definitely add pressure to Abe, whose support rate has been dropping due to pension-recording errors, as well as scandals and controversial remarks involving his cabinet ministers.

In 1998, the then prime minister Ryutaro Hashimoto was forced to resign after suffering a major setback in the election. Japan's top government spokesman Yasuhisa Shiozaki suggested Friday that Abe does not intend to step down even the election turned out to be a defeat for the governing bloc.