A task force formed by the main opposition Democratic Party of Japan agreed Monday to persist in demanding that economy minister Akira Amari provide a clear answer to allegations that he exchanged favors for money with a construction company.

"Diet questioning will start Tuesday. We want Mr. Amari to fulfill his responsibility to provide an explanation," Kazunori Yamanoi, head of the DPJ's "special assignment team," said at its first meeting.

DPJ Secretary-General Yukio Edano said separately that the party will continue to press Amari as well as Prime Minister Shinzo Abe through Diet debate.