Senior officials of Japan's ruling party agreed Monday to formally request that a party power-broker appear before a parliamentary ethics panel to answer questions.
Ichiro Ozawa, a former leader of the Democratic Party of Japan, is likely to be indicted next month in connection with alleged irregularities in a political fund he controlled. The scandal has helped undermine public support for Prime Minister Naoto Kan, whose disapproval rating stands at 65 percent or higher in recent polls.
DPJ Secretary General Katsuya Okada told reporters Monday that the party cannot expect the public's trust if it is not open about questions of money and politics. But the decision threatens to split the party, which has many loyal Ozawa supporters.
On Sunday, Chief Cabinet Secretary Yoshito Sengoku hinted that Ozawa should resign from the DPJ if he is indicted as expected.
Speaking on Asahi television, Sengoku said he believes Ozawa "will make a decision on his next course of action on his own." The phrase is commonly used in Japan to suggest a politician should resign.
Three former aides to Ozawa have already been charged in the case, which alleges that Ozawa's fund issued false reports concerning millions of dollars in 2004 and 2005.
The prosecutors have twice decided there is not sufficient evidence to charge Ozawa. But an independent panel of citizens has twice decided that he should be indicted. Under Japanese law, that leaves the prosecutors with no choice but to charge him.
Some information for this report was provided by Reuters.