An embattled Diet member who resigned as vice economy minister two days ahead of a magazine reporting on his alleged infidelity and "bigamy" is leaving the ruling Liberal Democratic Party as well.

Toshinao Nakagawa, 46, who stepped down as parliamentary vice minister of the Economy, Trade and Industry on April 18, submitted a written notice of resignation to the party on April 21. It is expected to be accepted by the end of the day.

Shukan Shincho (Weekly Shincho) magazine published a story on April 20 alleging Nakagawa's involvement in an extramarital affair and "bigamy" and being marked by police as a stalker.

Nakagawa responded to the allegations in Facebook posts, but has not made any other form of official statement.

“I took a liking to a woman whom I had known since when I was working as a company employee, despite having my own family, and I deeply hurt her,” he wrote on Facebook on April 18.

When the magazine hit the newsstands, he posted the same day, “I did nothing to be legally accused of bigamy, and the media is reporting as if I were accused of stalking (by police), but these are not true.”

With the revelations of the details of the scandal, a meeting of the Upper House Committee on the Economy and Industry on April 20 was thrown into turmoil, as opposition members adamantly demanded an explanation from Nakagawa.

A scheduled discussion at the meeting was canceled.

Kazuya Shinba, the chairman of the Upper House's Diet Affairs Committee of the main opposition Democratic Party, demanded that Nakagawa quit the Diet in an interview with the media on April 20.

“For the LDP’s sake and for the Diet's, he should resign as a Diet member,” Shinba said.

At a news conference on April 20, when asked about the demand by some opposition party members that Nakagawa resign as a Diet member, Chief Cabinet Secretary Yoshihide Suga brushed off Nakagawa, saying, “It is something he will decide for himself.”

According to a source, a core member of the LDP told a mid-ranking member of a party faction headed by LDP lawmaker Hiroyuki Hosoda, which Nakagawa belongs to, that it is better to “force him to leave the party soon.”

According to another source, senior LDP members, including Toshihiro Nikai, 46, the party's secretary-general, agreed on April 21 to encourage Nakagawa to leave the party in hopes of ending the embarrassing scandal as soon as possible.

Nakagawa remains a Diet member, representing a Hiroshima constituency.