TOKYO (AFP) - - Japan's beleaguered Prime Minister Shinzo Abe faces a battle for his political life as parliament opens Monday, with a newly empowered opposition set to do all it can to bring him down.

Abe's Liberal Democratic Party (LDP) was crushed in July elections after a raft of scandals, handing the opposition control of the upper house of parliament for the first time since the LDP was founded in 1955.

On the eve of the two-month extraordinary session of the Diet, Abe said he could resign if his government fails to win an extension of the mandate for Japan's mission in support of US-led troops in Afghanistan.

"Of course, I have no intention of staying in my job," Abe told reporters in Sydney, where he was attending a summit of Asia Pacific leaders, when asked whether he would resign if the mandate was not extended.

"I have to fulfill my duty by using all of my force," added Abe, who called the mission -- in which Japanese ships help refuel jets and ships operating in Afghanistan -- an official promise to the international community.

Abe has received support from a slew of Western nations for prolonging the mission. But the centre-left opposition wants Japan to bring home its ships and has not budged, setting the stage for Abe to suffer major embarrassment.

The embattled premier has called for direct meetings with the leaders of the opposition, who are also expected to flex their muscle by seeking symbolic censure motions against scandal-hit cabinet ministers and possibly Abe himself.

The main opposition Democratic Party of Japan quickly fired back at Abe over the refueling mission, showing they would not back down.

"It is like trying to solicit sympathy," party secretary general Yukio Hatoyama told Kyodo News.

"It doesn't mean much when it was said by a person who should have quit his job earlier," he added.

Abe, an outspoken conservative and Japan's first premier born after World War II, took office nearly a year ago with a popular, youthful image.

But his cabinet has been plagued by scandals and gaffes, with four ministers quitting and another committing suicide.

He reshuffled his cabinet on August 27 in hopes of a fresh start, but just one week later his new farm minister resigned over financial wrongdoing. Similar allegations have also been levelled against the latest farm minister.

With even some LDP backbenchers asking Abe to quit, analysts and media speculate it is only a matter of time before he steps down or calls a snap general election.

"Prime Minister Abe has resorted to a big gamble," Tetsuro Kato, professor of international politics at Hitotsubashi University in Tokyo, said following the prime minister's comments in Sydney.

Democratic Party leader Ichiro Ozawa, known as a brusque but shrewd political tactician, has instructed his supporters to get ready for early polls, saying the parliament session "may be an important turning point."

"I think a snap general election within this year or early next year is one of the scenarios," said Jun Iio, professor of politics at the National Graduate Institute for Policy Studies.

"If Abe's government proves to be too weak to operate in parliament, then the LDP may judge that a snap election at a very early date is better for them before the Democratic Party is completely ready for an election," he said.

But Iio thinks a more likely scenario is that Abe will eventually hand over to former foreign minister Taro Aso, a veteran LDP politician who became the party's secretary general last month, and Aso would then call a snap election.

In his policy speech to the lower house, Abe is expected to focus on "shadows of reforms" started by his popular predecessor Junichiro Koizumi, addressing the gap between cities and rural areas, which have not enjoyed the fruits of Japan's economic recovery, public broadcaster NHK reported.

Rural voters deserted the LDP in droves in the recent election, failing to relate to Abe's agenda, which focused on building Japan's global standing and rewriting the US-imposed post-war pacifist constitution.

"What Prime Minister Abe wishes would be to survive the upcoming parliament session and host the Group of Eight summit next year, where he expects to regain popularity, and then call a snap election next summer," Iio said.