Naoto Kan, secretary general of the Democratic Party of Japan, on Monday announced his candidacy for the largest opposition party's election next month.
"After exchanging views with different people, I have ultimately taken a firm resolve to run in the leadership election," Kan told a news conference in the Diet building. "If I become party head, I will work to present the advantages of the DPJ to the people and what reforms we can achieve, unlike the (ruling) Liberal Democratic Party."
He also said the DPJ's incumbent chief, Yukio Hatoyama, is not the kind of politician who fights relentlessly to persuade people but rather exerts himself on the basis of ideals, and is not particularly strong in debates between party leaders.
Kan, 55, has just returned from a visit to the United States at the invitation of the Center for Strategic and International Studies, a think tank in Washington.
He headed the DPJ from April 1998 until losing to Hatoyama, 55, in the September 1999 leadership election.
At the time, Hatoyama was the DPJ's deputy secretary general.
Speaking to reporters, Kan appraised the party's style of management as having gone a long way to build itself into a political party capable of taking the reins of government.
He said he envisions the party's leadership election leading to the toppling of the present administration of Prime Minister Junichiro Koizumi, and to reform of the present political scene.
The election, in which Kan will be up against other party heavyweights including Hatoyama and possibly younger members, is set for Sept. 23.