Chief Cabinet Secretary Kanezo Muraoka defended the Finance Ministry on Tuesday over the collapse of Yamaichi Securities Co., saying it would have been impossible for ministry officials to discover the brokerage had been conducting irregular, off-the-book trading.

He was speaking amid public criticism that the ministry, which is responsible for supervising and inspecting financial institutions, is partly responsible for the nation's financial turmoil. A number of lawmakers, including members of the ruling Liberal Democratic Party, have criticized the ministry for Yamaichi's collapse, saying the ministry lacks the ability to do its job and that it should have known about the firm's hidden wrongdoings and should have kept the information a secret. Hiromu Nonaka, deputy Secretary General of the Liberal Democratic Party, said during a meeting of LDP executives Tuesday that the ministry should take the blame for the financial confusion.

Meanwhile, Social Democratic Party Secretary General Shigeru Ito demanded Tuesday that the government recognize the ongoing financial turmoil as serious. He also urged it to make the utmost efforts to deal with problems related to the bankruptcy of financial institutions, Muraoka told reporters. During his meeting with Muraoka, Ito also said that Finance Minister Hiroshi Mitsuzuka should deal with the turmoil -- or his political career might be at risk.

Earlier in the day, six of the 15 members of the SDP in the Lower House abstained from voting at a plenary session during which a motion of no confidence in Mitsuzuka was submitted by three opposition parties. Although it was supported by members of Shinshinto, the Democratic Party of Japan, the Taiyo Party and the Japanese Communist Party, the motion was opposed by all members of the ruling bloc, excluding the six who abstained. All members of the SDP -- one of LDP's two allies -- were supposed to vote against the motion.