Japan's unpopular prime minister, Yasuo Fukuda, faced an unprecedented censure in parliament's upper house on Wednesday but the embarrassing opposition move was not expected to force him either to resign or call a snap poll soon.

The opposition Democratic Party and smaller allies submitted and were expected to approve the non-binding censure motion, the first against a prime minister under the 1947 constitution, in an effort to build momentum for an early lower house election.

Ruling party officials brushed off the motion as a political gesture. "It is very unclear why they are presenting a censure motion. If I am pushed, I would have to say that they are putting on a performance for the end of the parliament session," Kazuo Kitagawa, secretary general of the ruling coalition's junior partner, the New Komeito party, told a news conference.

No election for the powerful lower chamber need be held until September 2009, but Democratic Party leader Ichiro Ozawa has made no secret of his desire to force an early poll in the hope of ousting Fukuda's conservative Liberal Democratic Party (LDP), which has ruled Japan for most of the past six decades.

"I feel that he lacks the capability to be in charge," Ozawa told reporters on Tuesday. "Fundamentally, his only option is to seek the will of the people by calling a snap election," Japanese media quoted him as saying.

Fukuda's support rates have sunk to below 20 percent in some surveys on doubts about his ability to cope with a divided parliament. The opposition controls the upper house and has delayed legislation and blocked key appointments, including the government's first two choices for Bank of Japan governor.

ELDERLY OUTRAGE

Many Japanese voters would be happy to see the LDP lose its grip on power, but also have doubts about whether the Democrats, an often fractious group of former LDP members, ex-socialists and hawkish younger lawmakers, are ready to take the reins.

"I think the ruling party in Japan needs to change ... Our generation is the one that needs to push this kind of political change," said 33-year-old secretary Kanako Koga.

The 71-year-old Fukuda, a moderate known for favouring closer ties with Asian neighbours, has already indicated that he has no plan to step down as a result of the censure, which unlike a lower house no-confidence motion has no legal clout.

On Monday he told a news conference that his first priority was to deal with policy issues rather than call an election.

Ruling bloc lawmakers are reluctant to risk an election that could well see them lose the two-thirds majority that allows them to override upper house vetoes, if not their grip on power.

Tokyo stock market players, many of whom have already given up hope that Fukuda will implement bold reform policies, had little scope to ponder Japan's political saga.

"Political risk isn't something anybody's watching here. They're keeping their eyes out for companies' performances and with what happens to the global economy," said Hiroaki Osakabe, a fund manager at Chibagin Asset Management.

Data released on Wednesday showed Japan's economic growth revised up to 1 percent for the first quarter but it may be a last hurrah for the world's No.2 economy as surging raw material prices and a global economic slowdown bite.

Some said political deadlock could worry markets if the stalemate persists after the July 7-9 Group of Eight summit.

The ruling bloc is considering countering the censure motion with a confidence vote in the lower house.

Speculation persists that Fukuda might step down after hosting the G8 summit in northern Japan or that the LDP may replace him with former Foreign Minister Taro Aso or some other potentially more popular rival, perhaps later this year or early in 2009.

A parliamentary official confirmed that the Democrats and two smaller parties had submitted the censure motion, which media said targeted Fukuda for alleged missteps including the introduction of an unpopular medical insurance scheme that forces some people aged 75 and over to pay more for health care.

The confusing system outraged many elderly voters, long a core LDP constituency, and the Democrats want to abolish it.

No censure motion has been adopted against a prime minister under the post-World War Two constitution, but in 1998 then Defence Minister Fukushiro Nukaga - who now holds the finance minister portfolio - was forced to resign about a month after the upper house approved a censure motion against him.