Campaign for Japan's House of Representatives election slated for Dec. 16 kicked off Tuesday. Some 1,500 candidates from 12 parties are expected to run for the 480-seat Lower House.

As of now, the largest opposition party, the Liberal Democratic Party (LDP) headed by former Prime Minister Shinzo Abe, is leading in poll with a supporting rate of 18.4 percent, according to the latest weekend telephone poll by the Kyodo News Agency.

The newly founded Japan Restoration Party ranked the second with a support rating of 10.4 percent, closely followed by the ruling Democratic Party of Japan (DPJ) which gained 9.3 percent of supports.

However, more than 40 percent of respondents have yet to decide on which party they will vote for, according to the poll.

Besides the three parties, the rest are the Japanese Communist Party, the New Komeito Party which is an ally of the LDP, the New Party Daichi, the New Party Nippon, the New Renaissance Party, the People's New Party, the Social Democratic Party, Your Party and the Tomorrow Party of Japan which merged with the People's Life First Party led by influential political veteran Ichiro Ozawa.

In the election, 300 of the 480 seats will be elected from single-seat districts and the remaining 180 from proportional representation in 11 regional blocks.

Each voter will cast a ballot to a candidate run for the single- seat district and another ballot to a party for proportional representation.

A single-seat district runner can also appear in the candidate list of its party for the proportional representation so as to secure a seat in the House if the candidate's party wins competitions of the proportional representation system.

However, those who gained a seat through this way are required to be a member of a political party which has above five members in the Diet or won above 2 percent of total valid votes in the previous general election.

Voting process of the general election will start on Dec. 16. The Lower House was dissolved on Nov. 16 by Prime Minister Yoshihiko Noda, who is also the leader of the DPJ. Endi