Nine Democratic Party of Japan lawmakers have announced their candidacies or are contemplating running in the party's Sept. 23 presidential race. None, however, appears to have sufficient strength to dominate the nation's largest opposition party.

Incumbent Yukio Hatoyama, whose term ends next month, has been criticized as lacking the necessary leadership for the DPJ to mount an effective challenge to Prime Minister Junichiro Koizumi's ruling coalition, led by the Liberal Democratic Party.

Regardless of whether Hatoyama stays at the helm or is replaced, critics say the situation is unlikely to change.

"Since its foundation, one of the DPJ's tasks was to unify its ranks, who hail from various parties with different backgrounds and support groups," said Yasunori Sone, a professor of political science at Keio University. "However, the runup to the upcoming race has revealed that the party has failed to accomplish this task over the years."

The DPJ was established in 1996 and expanded two years later by incorporating opposition lawmakers from various groups, ranging from labor-backed politicians to conservatives who had deserted the LDP. The party has often been criticized for its factionalism, which is rooted in such groups.

"Although the leadership race is supposed to provide the party with centripetal force (to bolster solidarity), it is working as a centrifugal force instead," Sone said.

Some party members even worry that the DPJ may break up or suffer a series of defections.

"The party might split up depending on the situation," DPJ member Eisei Ito said, referring to Hatoyama's recent threat to expel members who refuse to toe the line laid down by the party's leaders.

In November, then party Vice President Takahiro Yokomichi and 21 other members ignored Hatoyama's decision and either voted against or abstained when the government sought Diet approval for its plan to dispatch Maritime Self-Defense Force ships to the Arabian Sea to provide logistic support for the U.S.-led war against terrorist targets in Afghanistan.

The move by the lawmakers, mostly former members of the Social Democratic Party, undercut Hatoyama's leadership. Yokomichi, who later was relieved of his post, has announced plans to run against Hatoyama in the September election.

Hatoyama ally Naoto Kan, DPJ chief from 1998 to 1999 and current secretary general, also plans to run.

Other veteran lawmakers ready to enter the race include Kansei Nakano and Tetsundo Iwakuni. Nakano is counting on support from DPJ members who formerly belonged to the now-defunct Democratic Socialist Party.

Junior lawmakers Seiji Maehara, Yoshihiko Noda, Takashi Kawamura and Shigefumi Matsuzawa have expressed their intention to run after voicing discontent with the current leadership.

The four are members of the Group to Create the Second Era of the DPJ, an intraparty assembly with more than 50 members calling for a rejuvenated leadership.

Junior lawmakers actually constitute a major force in the party. Of the 125 DPJ members in the Lower House, 89 have been elected to the Diet three times or less. Even so, their only hope of beating a veteran for the presidency is to rally behind a single candidate.

Members of this group are expected to decide by Tuesday whether to back a single candidate or simply allow all four to run.

The four junior lawmakers are currently jostling for support from colleagues, and a unified approach remains elusive. Veteran DPJ lawmakers, however, are apparently bracing for such developments.

"Don't be discouraged by the calls for rejuvenation of the party leadership," former Prime Minister Tsutomu Hata told Kan and Hatoyama at a Tokyo hotel this month.

Hatoyama has said he will resign from the Diet if he is defeated by one of the younger candidates.

By the time campaigning officially kicks off Sept. 9, some of the candidates are expected to drop out, because each one needs the endorsement of at least 20 DPJ lawmakers.

DPJ sources say Kan and Yokomichi will have no problem clearing that hurdle. But Hatoyama, who has led the DPJ for the past three years, may have trouble finding the numbers.

As for the junior lawmakers, Noda and Maehara are considered the front-runners, and attention is focused on whether one may bow out to support the other.

Whoever stays on the ballot, the winner will be hard to pick because party members are not the only eligible voters.

DPJ rules allow each of the party's 183 Diet members to cast two votes, while 83 members scheduled to run on the DPJ ticket in the next general election for the Diet, not including incumbents, have one vote each. Roughly 1,500 DPJ members in local assemblies nationwide will be given a total of 47 votes.

In addition, the party introduced a "supporter system" in which anyone over 18 who pays a 1,000 yen registration fee can vote. By mid-July, nearly 100,000 such voters had registered. Their ballots will be counted as the equivalent of 320 votes, or 40 percent of the total votes to be cast.

So far, Kan appears to have a head start. According to a recent Kyodo News public opinion poll, 31.3 percent of the 1,031 respondents named Kan as the most suitable leader for the DPJ, while 13.4 percent chose Hatoyama.

Yokomichi was supported by 6.1 percent and Nakano 3 percent. Each of the four younger candidates received the support of 2.5 percent or less, according to Kyodo.

Pundits say Kan, known for exposing in the mid-1990s the health ministry's role in the HIV debacle, and Yokomichi, who is expected to garner organized votes from labor unions, hold the advantage in votes from party supporters.

But Kan is unpopular with party members, so Hatoyama may have a chance to win another term if he can get support from the junior ranks, possibly in a runoff with Kan, the pundits said.