The ruling Democratic Party of Japan is planning to hold its presidential election on Sept. 14, DPJ sources said Friday. The vote will decide whether Prime Minister Naoto Kan remains in his post amid a gradual decline in support ratings.

The election date is expected to be formalized at a meeting of DPJ executives Monday, the sources said.

On Thursday, Kan voiced his eagerness to stay on as leader of the DPJ at a meeting of its Diet members.

All eyes are on what Ichiro Ozawa, the former secretary general, will do in the leadup to the election.

Ozawa heads the largest intraparty group, known to be critical of the way Kan has run the government.

The DPJ, which lost seats in the House of Councilors election July 11, considered holding the election on Sept. 11 or 12 but pushed the date back partly because it is behind in making the arrangements.