Lawmakers set to join a new party created through the merger of Japan's two largest opposition forces will vote on Sept. 10 to decide its name and leader, participating members said Tuesday.

The new force to be created by members of the Constitutional Democratic Party of Japan and the Democratic Party for the People aims to be a united front against the ruling coalition. It will hold a convention to mark its foundation on Sept. 15, they said.

Yukio Edano, head of the main opposition Constitutional Democratic Party of Japan, speaks at his party's meeting in Tokyo on Sept. 1, 2020. (Kyodo)

Yukio Edano, who heads the CDPJ, is considering announcing his leadership bid on Friday, they said.

"I would like to form a party that can take over the reins of government together with those who are from the DPFP and who are independent by making use of our past experiences," Edano said at a meeting of his party.

Meanwhile, the DPFP is aiming to have the party's policy chief, Kenta Izumi, run for the post as leader Yuichiro Tamaki will not join the new party due to differing views with the CDPJ on policy issues.

The launch event was originally scheduled to be held on Sept. 16, but it was brought forward as an extraordinary parliament session to pick Japan's next prime minister is expected to be convened on the same day. Incumbent leader Shinzo Abe suddenly announced his resignation on Friday.

Ichiro Ozawa, veteran lawmaker from the DPFP, told a press conference on Tuesday that he will support Edano in the leadership election, but said it is not an ideal time to hold it since there are "rumors" about the possibility of the lower house being dissolved for a general election.

The CDPJ currently has 89 lawmakers -- 56 in the House of Representatives and 33 in the House of Councillors. The 62-member DPFP has 40 and 22 lawmakers in the lower and upper chambers, respectively.

Most of the 62 DPFP members are expected to join the new party, in a move that would create a force with about 150 lawmakers including those currently belonging to independent groups.

Even after the merger, however, the new party would still fall far short of the more than 450 seats in both chambers held by Abe's Liberal Democratic Party, its junior partner Komeito and their supporters.

The LDP will hold a leadership election on Sept. 14 and its winner is expected to be named as the new prime minister at the extraordinary Diet session as the ruling party controls the powerful lower house.

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