The government on Thursday accepted the resignation of Taro Yamada, a member of the ruling Liberal Democratic Party, as parliamentary vice minister for education and post-disaster reconstruction over an extramarital affair.

Yamada, 56, is the first to have quit among ministers, state ministers and parliamentary vice ministers since Prime Minister Fumio Kishida reshuffled his Cabinet in mid-September. Yamada tendered his resignation Wednesday.

The development will be certain to deal a blow to Kishida at a time when public support rates for his Cabinet have plummeted.

On Thursday, the government appointed Akiko Honda, an LDP member and lawmaker of the House of Councilors, to replace Yamada as parliamentary vice minister for education, culture, sports, science and technology and for post-disaster reconstruction. Honda, 52, is the only woman among state ministers and parliamentary vice ministers.

Weekly magazine Shukan Bunshun reported that Yamada, an Upper House member elected under the proportional representation system, has had an affair with a woman in her 20s. "I deeply apologize," Yamada told reporters at parliament, admitting to the affair.

"I wanted to prevent the matter from becoming an obstacle to parliamentary business," he said, explaining the reason for deciding to resign as parliamentary vice minister.

Yamada said he does not plan to resign as a lawmaker at the moment. "I have never given cash (to the woman in her 20s) in exchange for a sexual relationship," he said.

At a news conference Thursday, Akira Nagatsuma, policy chief of the main opposition Constitutional Democratic Party of Japan, urged Yamada to give a full explanation about the matter. "He must never hide (from accountability)," Nagatsuma said.

At a separate news conference the same day, Deputy Chief Cabinet Secretary Hideki Murai also said that Yamada needed to fulfill accountability.