The House of Representatives approved Tuesday the resignation of opposition lawmaker Hisayasu Nagata for disrupting Diet business by using a fake e-mail message to attack a top Liberal Democratic Party official.

With the resignation of Nagata, whose membership in the Democratic Party of Japan has been suspended, Motohisa Ikeda will take over his seat in the Lower House. Ikeda was a runnerup on the DPJ's list of candidates for the proportional portion of the ballot in last September's general election.

Nagata, 36, submitted his resignation Friday. DPJ President Seiji Maehara also announced the same day he plans to resign his party post, together with other DPJ executives, to take responsibility for the incident. The party is scheduled to elect his successor Friday.

During a Diet committee session Feb. 16, Nagata alleged on the basis of the fabricated e-mail message that arrested Livedoor Co. founder Takafumi Horie had ordered a subordinate to pay 30 million yen to a son of LDP Secretary General Tsutomu Takebe before the general election, in which Horie ran unsuccessfully but received Takebe's support. Horie has been charged with violating the Securities and Exchange Law.

The Lower House Disciplinary Committee had initially decided to summon Takashi Nishizawa, the freelance journalist who provided the printed e-mail message to Nagata, for sworn testimony Tuesday but abandoned the plan in light of Nagata's resignation.

Nagata, a University of Tokyo graduate and former Finance Ministry bureaucrat, had been elected three times to the Lower House since 2000.

Ikeda, 65, a Waseda University graduate and former political reporter at NHK, was elected four times to the lower chamber starting in 1990 before losing last September.