Former ruling Liberal Democratic Party lawmaker Mito Kakizawa on Wednesday pleaded guilty to charges of illegal campaign financing in relation to a Tokyo ward election last April.

"I have decided not to contest any of the charges," the 53-year-old former senior vice justice minister said at the first day of his trial at the Tokyo District Court, acknowledging the "heavy" responsibility he bore.

Kakizawa has been indicted for violating the election law by making or offering bribes to the tune of about ¥2.8 million ($19,000) in connection with the Koto Ward mayoral election, in which former LDP lawmaker Yayoi Kimura — a candidate he backed — won.