TOKYO - Three former aides of a Japanese ruling party powerbroker were convicted Monday in a political funding scandal, dealing a further blow to his status in the struggling party ahead of his own trial.

Ichiro Ozawa engineered the Democratic Party of Japan's rise to power in 2009, but was charged this year with political funding violations for allegedly overseeing false accounting by his aides.

The Tokyo District Court gave the former aides suspended prison terms ranging from one to three years for accepting $1.3 million (100 million yen) in illegal donations from a construction company and for failing to register a $5.2 million (400 million yen) loan from Ozawa to his funding body in a 2004 Tokyo land deal.

All three aides have denied any wrongdoing, as has Ozawa, who says he is confident of proving his innocence at his own trial, which starts Oct. 6.

Opposition leaders were quick to attack Prime Minister Yoshihiko Noda's 3-week-old government after the ruling.

Opposition Liberal Democratic Party lawmaker Nobuteru Ishihara said the aides' convictions were serious and "their boss, Ichiro Ozawa, bears even more serious political responsibility."

He demanded that Noda, as ruling party leader, take appropriate steps such as asking Ozawa to resign.

Noda declined to comment, citing the judiciary's independence.

The scandal has damaged Ozawa's ambitions to become prime minister, and he remains unpopular with voters who widely see him as an old-school, backroom wheeler-dealer.

Nevertheless, Ozawa, 69, continues to wield a great deal of influence and has a loyal core of supporters within the party. Last year, he lost a party leadership vote to then-Prime Minister Naoto Kan, but several months later he played a key role in pressuring Kan to resign.

Ozawa will stand trial after a judicial panel composed of ordinary citizens sought his indictment, despite an earlier decision by prosecutors that there was insufficient evidence to proceed.

In Monday's ruling, the aides' sentences were all suspended for several years, meaning that none will go to prison unless they commit new crimes during that period.