With Prime Minister Yoshiro Mori's resignation imminent, observers predict his most likely successor may be ruling party heavyweight Hiromu Nonaka, a man many say is unlikely to pull the nation out of its current political and economic quagmire.

Although Nonaka has repeatedly denied he intends to run in the next Liberal Democratic Party presidential election, which could be held as early as April, observers say the party's 75-year-old former secretary general will eventually turn out to be a key candidate in the race that will effectively determine the next prime minister.

So far, no one has declared their candidacy.

Given that the support bases of the LDP and its coalition partners, New Komeito and the New Conservative Party, rely largely on traditional industries that are currently in decline, the ruling camp seems unlikely to select any reform-oriented politician to be the next leader -- especially with the critical Upper House election only four months away, according to Fukashi Horie, president of Shobi University in Saitama Prefecture and a political scientist.

Leading figures among the LDP's allies are openly requesting that Nonaka take over from Mori, citing his achievements in establishing and maintaining the current tripartite ruling coalition.

They also applaud his stance on preserving the status quo -- with the notable exception of his notion of reviewing the public servant system and scrapping semigovernmental organizations.

But if Nonaka is to head the governing camp during the July election, it is unlikely that unaffiliated voters -- who in recent elections have deserted the LDP -- will vote for the ruling triumvirate, Horie said. This scenario, he added, will leave the three parties no choice but to attempt to consolidate organized votes from their traditional supporters.

"It may be good if the fixer (Nonaka) himself takes center stage, because the next prime minister will not be remote-controlled any more," Horie said.

Nonaka is one of the top LDP executives who reportedly handpicked Mori as the successor to Keizo Obuchi, who last April suffered what turned out to be a fatal stroke. Nonaka is also believed to be the one who pressured Mori into promising to move up the LDP election when the prime minister met Saturday with party elders.

"One thing that Mori may deserve our sympathy for is that he could not decide (the government's) basic policies himself. He is a puppet prime minister who merely implemented the policies of such figures as Nonaka and (LDP policy chief Shizuka) Kamei," Horie added.

Despite his age, Nonaka's powerful -- occasionally menacing -- political skills are qualities that have won the respect of many of his colleagues.

"He may prove to be popular among insiders in political circles," Horie said.

But the general public may prefer Junichiro Koizumi -- a popular reform-oriented LDP member -- over Nonaka, who is often perceived as a backroom tactician versed in the old "Nagata-cho" ways of politics.

Many observers believe, however, that should Koizumi, a 59-year-old former health minister, become the next prime minister, he would probably fail to carry out many of his trademark reform proposals.

These include a controversial plan to privatize inefficient state-run postal services and efforts to rebuild the nation's fiscal health.

"Even if Koizumi becomes the prime minister, he won't be entrusted (by LDP heavyweights) to carry out reforms," said Jun Iio, a professor of political science at the National Graduate Institute for Policy Studies in Tokyo. "Then, he would be caught up in a dilemma between his reform attempts and being in the LDP.

"He is crying alone for reform. Nobody else in the Mori (LDP) faction (which Koizumi currently chairs) is tuning in to him."

However, political commentator Hisayuki Miyake predicts that if the LDP holds its presidential election in a transparent manner, Koizumi, dubbed an eccentric by his colleagues, could win because of his candor and popular appeal.

Miyake predicts that the delicate balance within the LDP's largest faction, which is led by former Prime Minister Ryutaro Hashimoto and to which Nonaka belongs, may cause problems for a prospective leadership bid by Nonaka.

The faction, believed to hold the key to the selection of Mori's successor, will have difficulty agreeing on a common candidate since the group's pendulum of power sways between Hashimoto and Nonaka.

Hashimoto currently serves as state minister in charge of administrative reform and does not seem to be wholly averse to the notion of a possible prime-ministerial comeback.

Observers also say that Nonaka cannot necessarily count on the full support of his factional colleagues, who are reportedly jealous of his rapid ascent to top posts within the LDP in recent years despite his relatively short career as a Diet member. Nonaka entered politics initially as a local assemblyman in Kyoto Prefecture and is now serving his seventh term as a Lower House member.

The Hashimoto faction is also afraid that should one of their members succeed Mori, the faction will have to shoulder the blame if the ruling camp suffers a setback, as anticipated, in the Upper House election in July, he said.

Aside from these names, Taku Yamasaki, who joined his ally Koichi Kato in an abortive revolt against Mori in November, and a few junior LDP lawmakers who have also been critical of Mori have signaled their intention to run in the presidential race.

The mainstream factions in the LDP that have supported Mori apparently hope to maintain cozy ties in the selection of a new leader. Pundits predict, however, that the battle for power among these groups may intensify if both Nonaka and Koizumi eventually refuse to run and another candidate has to be found.