Ichiro Ozawa's efforts to persuade voters to end the Liberal Democratic Party's almost-uninterrupted 50 years of rule and bring his party to power may be set back by reminders of his links to disgraced former LDP lawmakers.

Last week's arrest of his chief secretary, Takanori Okubo, for alleged violation of the political funds law probably will hurt the Democratic Party of Japan in the general election that must be held by fall and weaken Ozawa's leadership, DPJ lawmakers say.

"Should the allegations prove true, then Mr. Ozawa will have to decide what his responsibility is," said Motohisa Furukawa, a member of the Lower House and a former Bank of Japan official. "It's a fact that this case has meant major damage to our party."