Japanese Prime Minister Taro Aso has been driven into a tight corner as a group of his ruling Liberal Democratic Party (LDP) lawmakers Thursday called for a key decision-making panel this week to oust him.

Up to 133 signatures of the LDP lawmakers, including those of former LDP Secretary General Hidenao Nakagawa, the incumbent Finance Minister Kaoru Yosano and farm minister Shigeru Ishiba, were submitted to urge the LDP leadership to hold the panel, officially known as the Joint Plenary Meeting of Party Members of Both Houses of the Diet.

"Now that the signatures have been collected, it is the LDP's responsibility to hold the meeting if the party boasts democratic procedures," Yosano was quoted as telling reporters earlier in the day.

"I share the concerns, and I will make preparations so the party will be able to unite in facing the next battle," said LDP Secretary General Hiroyuki Hosoda upon receiving the signatures,

To open the panel, at least 128 signatures, or a third of the 384 LDP lawmakers, must be collected. And under party rules, the LDP must convene the meeting within seven days after the signatures are submitted.

On Wednesday, LDP lawmakers started a petition drive that could set the stage for Prime Minister Taro Aso's ouster before the lower house election next month.

Three former LDP secretaries-general -- Nakagawa, Tsutomu Takebe and Koichi Kato -- have all separately raised questions about the merit of Aso leading the LDP into the Aug. 30 election.

Analysts here said that the LDP leadership may not accept a request to hold an official joint plenary meeting of its Diet members.

Aso said late Wednesday that he left the handling of the matter to LDP Secretary General Hiroyuki Hosoda.

"A non-confidence motion against my cabinet was rejected (by the Diet). That means I won the confidence of all the LDP lawmakers who participated in the Diet session. So I'll speak as a prime minister who has won the confidence (of his party)," said Aso.

Finance Minister Yosano was believed to have tacitly urged Aso Wednesday to resign in response to the LDP's historical defeat in Sunday's Tokyo Metropolitan Assembly poll, The Daily Yomiuri reported Thursday.

Yosano, however, denied such media reports.

"I'm aware that there are some reports saying that. But they are not true," said Yosano Thursday in response to the question as to whether he urged Aso to resign voluntarily during their talks Wednesday at the premier's office.

Yosano, one of the most influential members of Aso's Cabinet, has started to distance himself from the premier after the Liberal Democratic Party suffered a crushing defeat in Sunday's Tokyo Metropolitan Assembly election, during which the opposition Democratic Party of Japan (DPJ) garnered 54 seats out of the total of 127, compared with 38 seats for the Liberal Democratic Party (LDP) and 23 seats for the New Komeito party.

The ruling coalition faces real challenges as the ruling bloc of the LDP and the New Komeito party failed to achieve its target of retaining a majority.

Aso's leadership ability was challenged after a series of ministerial resignations. There has been voices from some LDP legislators asking him to step down. However, many analysts believed that even changing the leader could not save LDP's fate in the election.

(Xinhua News Agency July 16, 2009)