The second largest opposition party, Japan Restoration Party, on Sunday formally decided to disband and split into two parties.
Co-leader and Osaka Mayor Toru Hashimoto addressed party members at a conference in Osaka, while party co-founder Shintaro Ishihara joined via video link from Tokyo.
Hashimoto and Ishihara made the decision last month to go their separate ways over differences on a proposed merger with the Unity Party and constitutional reform.
The Unity Party rejects Ishihara's drive to scrap the U.S.-inspired post-World War II constitution. Ishihara, 81, told the meeting that he cannot accept the view of the Unity Party because it does not accept the establishment of an independent constitution, TBS reported. He said that he will support Prime Minister Shinzo Abe in some areas, such as moves to reinterpret the constitution to allow the right of collective self-defense.
Ishihara has long advocated the creation of a new constitution which allows Japan to have strong armed forces which can go to war. The present charter bans the use of force in settling international disputes.
Ishihara's own Sunrise Party joined Hashimoto's in late 2012, when he renounced the Tokyo governorship to return to national politics through general elections in which the conservative Liberal-Democratic Party (LDP) regained power with a landslide victory.
But the two men have differed on important issues including nuclear power.
Ishihara has pushed for the restarting of nuclear reactors which were switched off after the 2011 earthquake and tsunami sparked meltdowns at the Fukushima nuclear power plant.
Hashimoto told the Osaka gathering he was sorry the party had to dissolve. However, he said he will go back to basics and make a fresh start as a new opposition force.
The LDP has a solid majority of 295 seats in the lower house and a near-majority 115 seats in the upper house, where it is aligned with the New Komeito Party.
The Japan Restoration Party has 53 seats in the 480-seat lower house of parliament and nine in the 242-seat upper chamber. The Unity Party has nine seats in the lower house and five in the upper house.
Of the 62 Japan Restoration Party lawmakers, 37 will join Hashimoto, 23 will go with Ishihara, while two will become independents.
The two new parties are expected to be formed by the end of July.© Japan Today/AFP