Speculation that Prime Minister Junichiro Koizumi will reshuffle his Cabinet sometime after the current Diet session ends Dec. 7 has not ebbed, despite his repeated denials.

Experts are mixed on whether a Cabinet reshuffle at this time would prove beneficial or damaging to Koizumi, who still retains strong popular support but faces a possible showdown with the Liberal Democratic Party, which he heads, over his reform initiatives.

Pressures on Koizumi to change his Cabinet lineup have mounted, particularly from LDP lawmakers who claim Foreign Minister Makiko Tanaka, who is embroiled in a continuing standoff with ministry bureaucrats, should be replaced because she is not doing her job properly on the diplomatic front.

But the Tanaka factor appears to be only one of the reasons why senior LDP members want a Cabinet reshuffle.

Koizumi made it clear earlier this week that he has no intention of reshuffling his six-month-old Cabinet. When he took office in April, he declared that he would keep his ministers as long as he remains at the helm.

"LDP members always call for a Cabinet reshuffle," Koizumi said. "But it has only been six months (since the Cabinet was formed)."

He was referring to a trend by many prime ministers to change their Cabinet at short intervals -- often within a year and sometimes even shorter. This has been blamed as a major reason why many lawmakers appointed to Cabinet positions end up relying on bureaucrats on policy matters and are replaced before they can build up their own expertise.

But few people in Nagata-cho -- the center of the nation's politics -- seem to take Koizumi at his word.

Leaders of the various LDP factions have maintained their power by distributing Cabinet or party positions to their members. A Cabinet reshuffle is an important occasion for them to flex their muscles.

Former Prime Minister Yoshiro Mori, who heads an LDP faction to which Koizumi belonged until he quit the group in April, is one of the most vocal advocates of a Cabinet reshuffle.

"A reshuffle brings in new energy to the Cabinet," Mori, whose resigned with extremely low public support ratings, paving the way for Koizumi's ascent to power, recently told reporters.

When Koizumi became LDP president and prime minister in April, he pledged to fight against the party's factional politics and mostly bypassed factional leaders in the selection of his Cabinet. In particular, the faction led by former Prime Minister Ryutaro Hashimoto, the LDP's biggest group, was ignored.

While this earned Koizumi wide public support as a reformist, the LDP's old guard was disgruntled. His opponents remained quiet in the initial phase of his highly popular administration, but they could pose serious resistance to his reform efforts, especially his bid to streamline or privatize money-losing government-affiliated corporations.

Political commentator Hisayuki Miyake says Koizumi is apparently torn between two options: Gaining a more solid footing within the LDP but giving in to factional politics, or maintaining the reformist orientation of his Cabinet despite an unstable power base within the party.

"If he reshuffles the Cabinet, his public support rate will fall and his structural reform policy may falter" because he will have no choice but to accept requests from the Hashimoto faction in the appointments of new Cabinet members, Miyake said.

"But (support from the Hashimoto faction) will add stability in the administration," he added. "(With Tanaka increasingly under fire from within the ruling camp), I think Koizumi has no choice but to reshuffle the Cabinet."

Others say the Hashimoto faction, many of whose members have openly expressed opposition to Koizumi's reforms, will seize the opportunity of a Cabinet reshuffle to regain influence over party affairs and possibly control over the prime minister.

"A reshuffle would only damage the Koizumi Cabinet," said Muneyuki Shindo, a professor of political science at Rikkyo University.

Shindo noted that, for example, conservative LDP members hope to replace Hakuo Yanagisawa, minister in charge of financial affairs, and Heizo Takenaka, minister for economic and fiscal policy. Many in the LDP's old guard have openly expressed resentment that Koizumi bypassed the party and relied on Takenaka, an economist, in formulating his economic reform policies.

Nobuteru Ishihara, state minister for administrative and regulatory reforms, is also the target of lawmakers who oppose privatization of government-linked public entities, he said.

Calls are also surfacing within the LDP and its coalition partners that Taku Yamasaki, LDP secretary general and a longtime Koizumi ally, be removed from the position simultaneously with a Cabinet reshuffle.

A senior lawmaker within the coalition said this reflects growing discontent toward Yamasaki among New Komeito leaders and LDP members who have cherished the current framework of the tripartite coalition. Many such LDP lawmakers belong to the Hashimoto faction.

Koizumi has frequently hinted that he would not stick to the alliance with New Komeito and indicated his willingness to forge closer ties with the Democratic Party of Japan if the largest opposition party is ready to support his reform initiatives.

The prime minister and Yamasaki sought cooperation from the DPJ in the recent Diet enactment of a law to enable Self-Defense Forces to provide noncombat support to U.S.-led antiterrorism operations. But the attempt failed in the last minute after the LDP's coalition allies opposed major revisions to the legislation to accommodate DPJ demands.

Yamasaki was also criticized following the failure of the coalition to agree on partial changes to the House of Representatives electoral system, which had been strongly advocated by New Komeito. Yamasaki was the key negotiator with his coalition counterparts on the issue.

"Yamasaki caused confusion several times (in the coalition discussions on the antiterrorism legislation and electoral reform) because he leaked information (to the media) in the course of negotiations," a senior member of New Komeito said on condition of anonymity.