The ruling Democratic Party of Japan (DPJ) started presidential election Friday morning, with Finance Minister Naoto Kan leading the race.

The 63-year-old Kan, also deputy prime minister, is reportedly to have gained broad support from DPJ lawmakers, including Foreign Minister Katsuya Okada and Transport Minister Seiji Maehara.

Kan will be challenged by Shinji Tarutoko, 50, a relatively unknown lawmaker who chairs the House of Representatives Environment Committee.

The election started at 9 a.m. when the party started accepting candidacy. A general meeting of party lawmakers from both chambers of the Diet opened at 11 a.m. in the Diet Building, where 307 lower house members and 115 House of Councilors members will cast ballots to choose their new leader.

The election occurs at a time when the DPJ is experiencing hardships as well as is a test for the ruling party, said Tarutoko at the general meeting of DPJ Diet members before the vote began, calling for a more unified DPJ.

Not a senior lawmaker as he is, he is willing to exert continued efforts to be a qualified leader, he said.

Kan, for his part, said that he will strive to help the DPJ out of the current predicament.

"I plan to achieve a strong economy, public finances and social welfare system in a unified manner," he said.

Yukio Hatoyama and his Cabinet members resigned en masse in the morning, prior to the Diet's vote on the country's new leader.

The new DPJ president, who is expected to be named at around 12: 30 p.m. is almost certain to become Japan's next prime minister as the party holds a comfortable majority in the powerful lower house.

Hatoyama announced his resignation Wednesday, bowing to pressure within the DPJ due to his handling of a U.S. base relocation in Okinawa and fund problems.

A provisional public opinion poll conducted nationwide by The Yomiuri Shimbun on Wednesday and Thursday showed the support rate for the DPJ climbed to 29 percent from around 20 percent at the weekend after Hatoyama and DPJ Secretary General Ichiro Ozawa resigned. The survey said 69 percent of the respondents supported their resignation.