The Democratic Party of Japan, which trumped Abe's ruling coalition in the July 29 elections for the upper chamber, also said it might call for an end to the country's air force mission to support U.S. operations in Iraq — setting up a showdown over a key tenet of Japanese foreign policy.

"The makeup of the upper house has drastically changed after the upper house elections, and we face a political landscape we have never before experienced," veteran DPJ lawmaker Satsuki Eda said after the upper house unanimously voted him chairman at the start of a special session today.

"I am keenly aware of the gravity of my responsibilities," he said.

Eda is the first opposition lawmaker to hold the post since the ruling Liberal Democratic Party began 50 years of almost uninterrupted political domination in 1955.

The party suffered one of its worst setbacks in 50 years in last month's elections, while the Democrats now dominate the 242-seat upper house for the first time with 113 seats.

Though Abe's ruling coalition still controls the more powerful lower house, which chooses the prime minister, the Democrats' advance in the upper house is expected to make it difficult for the ruling bloc to pass legislation.

The government has already been weakened by a series of scandals that have led to the departure of four Cabinet ministers. Support for Abe's Cabinet has dipped to a record low of 22 percent, according to a telephone poll of 1,165 voters conducted Aug. 4-5 by the national Mainichi newspaper.

Japanese media reported a new scandal Tuesday, alleging that Justice Minister Jinen Nagase illicitly received a donation from an advocacy group in return for expediting inquiries to the ministry about visa procedures for a group of Chinese workers.

Nagase allegedly received $4,200 before he became justice minister and the money was returned to the group this year, according to Kyodo News agency. The group promotes the use of cheap foreign labor in Japan, Kyodo said.

Nagase denied any wrongdoing during a news conference aired by public broadcaster NHK on Tuesday.

DPJ leader Ichiro Ozawa signaled Tuesday that he may try to end Japan's mission to airlift coalition personnel and supplies from Kuwait to Iraq in support of U.S.-led operations there.

Japan has been a staunch supporter of the U.S. invasion of Iraq, dispatching troops there in 2004-2006. Japan's air force continues to transport coalition personnel and supplies from Kuwait to Iraq.

But Ozawa, who has argued that Japan's international efforts should be channeled through the United Nations and not the United States, said he was mulling a bill to cancel the airlift operations for Iraq. Ozawa has already said he intends to oppose extending a naval mission to the Indian Ocean to provide logistical support for U.S. operations in Afghanistan.

"Be it Afghanistan or Iraq, I don't think Japan-U.S. relations are all about following the Bush administration's policies," he said.