Speculation is growing that Prime Minister Yoshiro Mori may remain in his post beyond April, partly because of the recent decline in share prices and the confusion over just who would succeed the unpopular leader.

LDP policy chief Shizuka Kamei insists the intraparty vote to choose Mori's successor as LDP president and prime minister should not be held until after emergency measures to bolster the sagging economy are implemented.

On Thursday, Hiromu Nonaka, a former party secretary general and one of the likely candidates to slide into Mori's throne, reiterated that the economy must take precedence over the party election.

Mori proposed Saturday that the party election be moved up so a new leader can better prepare the party for the crucial Upper House poll in July. Speculation has been rife since then that Mori will officially announce his resignation once the fiscal 2001 budget and its related bills clear the Diet in early April, paving the way for a party election later in the month.

While Kamei has said the party election should be delayed until June, Nonaka has told reporters that would be too long.

Coalition partners New Komeito and New Conservative Party, which hope to see Mori replaced as early as possible, were quick to rebuff Kamei's drive and launched renewed calls for Mori to step down next month.

Opponents to an early LDP election are now citing the continuing slump in the Tokyo stock market. The benchmark 225-issue Nikkei index's temporary fall Thursday below 11,500 -- the lowest since December 1984 -- sent shock waves through the country before it closed up at 12,152.83.

Earlier in the day, Mori launched another task force to propose measures to rescue the market. The ongoing crash of share prices in Japan and abroad is likely to top the agenda at Mori's talks with U.S. President George W. Bush on Monday.

Those favoring an early LDP election, meanwhile, cite the negative effect the leader is having on market confidence in Japan.

Former trade minister Mitsuo Horiuchi told a Thursday gathering of his LDP faction that the Mori Cabinet should step down immediately after the budget is passed and pave the way for a new administration that can turn the economy around.

The need to address the economy is not the only factor impacting the timing of Mori's ouster. His likely successor also remains a mystery, as prospective candidates clam up in unison.

A behind-the-scenes battle seems to be under way and it remains unclear whether a strong candidate can be identified by party heavyweights in time for an election in April.

Nonaka, who appears the most likely successor, continues to deny his candidacy -- apparently because of internal friction within his LDP faction, which is led by former Prime Minister Ryutaro Hashimoto. Nonaka's candidacy may upset the delicate power balance within the group.

By denying his intention to run, Nonaka could also be trying to dodge speculation that he pressured Mori to move up the LDP presidential election to make way for his own ascendancy, party sources say. Another prospective candidate is former Health Minister Junichiro Koizumi, but he also has remained quiet on the issue, apparently due to his awkward position as No. 2 man in Mori's faction, they said.