The move by the Liberal Democratic and New Komeito parties showed increasing willingness to challenge Prime Minister Naoto Kan's management of the recovery from a March 11 earthquake and tsunami and resulting nuclear crisis, the Kyodo News reported.
The multiparty ''reconstruction implementation headquarters'' had been proposed by Shizuka Kamei, leader of the People's New Party, the coalition partner of Kan's Democratic Party of Japan.
The opposition also said it would vote against a bill outlining reconstruction of the northeastern Tohoku region and not join a Reconstruction Design Council.
LDP leader Sadakazu Tanigaki and New Komeito leader Natsuo Yamaguchi said they will instead ask the DPJ to establish reconstruction committees in each of the two Parliament chambers.
LDP Vice President Tadamori Oshima said the opposition might submit a no-confidence motion against the government.