Tokya: Japan's lower house elected Naoto Kan as the new prime minister Friday, handing the outspoken, grass-roots populist the task of quickly reclaiming public support squandered by his predecessor ahead of July elections.

"My task is to rebuild this nation," Kan said after he was chosen ruling party chief. Pledging to confront problems linking "money and politics," he also stressing the need to spur economic growth.

Kan, 63, was finance minister under the unpopular Yukio Hatoyama, who stepped down Wednesday amid plunging approval ratings over broken campaign promises and a political funding scandal.

As prime minister, Kan faces daunting choices in how to lead the world's second-largest economy, which is burdened with massive public debt, sluggish growth and an aging, shrinking population. He must also rally voter support ahead of upper house elections next month.

Kan, known for standing up to Japan's powerful bureaucrats, is the country's sixth prime minister in four years.

"We will work together as one in the face of the tough political situation and the upcoming upper house election and fight together unified," he said after the party vote.

"Our first priority is to regain the trust of the people."

The path to the parliamentary vote began in the morning, when Hatoyama's Cabinet resigned en masse. Then the ruling Democratic Party of Japan voted Kan as its new leader. The lower house convened a couple hours later to approve Kan as prime minister.

Kan received 313 votes out of 477, with Liberal Democratic Party head Sadakazu Tanigaki getting 116. The rest went to other candidates of smaller parties.