Opposition lawmakers intensified their calls Saturday for Foreign Minister Seiji Maehara to resign over an illegal donation from a Korean resident of Japan, but Democratic Party of Japan Secretary General Katsuya Okada defended him.

Nobuteru Ishihara, secretary general of the Liberal Democratic Party, said, "It is a grave crime that entails suspension of civil rights if he is confirmed guilty under the Political Funds Control Law."

Maehara admitted Friday at a news conference that he received ¥50,000 from the South Korean woman, in violation of the law banning such contributions to prevent domestic politics from being influenced by foreign powers.

New Komeito joined the call for his resignation. "Maehara should take responsibility," Deputy Secretary General Yosuke Takagi said.

Maehara, meanwhile, expressed his determination to stay in office during a news conference Saturday in Kitakyushu, where he was visiting.

"It is important for me to perform my duties and give a clear explanation" of the donation scandal, he said.

The DPJ's Okada, while admitting the donation was illegal, defended Maehara.

"It is questionable if a minister must resign each time due to a clerical oversight," he said.