Lawmakers in key positions should disclose details of their office expenses to regain public trust, Democratic Party of Japan leader Ichiro Ozawa said Monday in a challenge to Prime Minister Shinzo Abe.

Under the Political Funds Control Law, lawmakers are required to itemize and provide receipts for money spent on political activities, but not for "office expenses."

Recently, however, several key lawmakers, including agricultural minister Toshikatsu Matsuoka, education minister Bunmei Ibuki, and Shoichi Nakagawa, policy chief of the ruling Liberal Democratic Party, have drawn fire for declaring enormous "office expenses" in their political funding reports while using rent-free government offices.