Political pundits said it remains to be seen whether or not DPJ can remain in unity after already having lost one prime minister since taking power for the first time a year ago.
Kan will be hoping that public sentiment will influence party members' decision making and ensure his immediate future as the party and the nation's leader.
A total 73 percent of voters surveyed by the Nikkei newspaper recently said they wanted Kan stay in office, compared with just 17 percent who hoped for Ozawa's victory.
Similarly, a poll by the Yomiuri Shimbun showed 67 percent of respondents favored Kan compared to just 14 percent for his opponent.
Meanwhile, 70 percent of voters surveyed by Kyodo News said they supported Kan, compared with 16 percent for Ozawa.
Ozawa stepped down as party leader last year over a political funding scandal and resigned as the party's No.2 in June.