The ruling Democratic Party of Japan reinstated the party membership of Ichiro Ozawa on Tuesday, a move that intensifies the power struggle over a proposed tax hike the DPJ heavyweight opposes and opens the door for him to run in the party presidential election in September, when Prime Minister Yoshihiko Noda's term expires.

Members of the DPJ Standing Officers Council made the decision following a ruling last month by the Tokyo District Court exonerating Ozawa of falsifying the political funds report of his fund management body.

Lawyers who acted as prosecutors at Ozawa's trial will decide Wednesday whether to appeal the decision to the high court. Some party members, including policy chief Seiji Maehara, were against lifting Ozawa's membership freeze before the lawyers' decision.