"A long way is still ahead of us, but we will continue working hard."

Timing challenged

The Democratic Party of Japan (DPJ), the main opposition party, called the timing of the lower house vote a gift from Fukuda to George Bush, the US president.

Fukuda is due to leave on Thursday for the US, Japan's main ally, on his first foreign trip since taking office in September, the government said on Monday.

The ruling coalition "forced a vote for the bill because they desperately needed a souvenir for the US visit and summit", Yukio Hatoyama, DPJ secretary-general, said.

However, Bunmei Ibuki, the secretary-general of the ruling Liberal Democratic party (LDP), said that passing the bill in only the lower house was not good news for Fukuda to take to Washington.

He said: "If the DPJ deliberates on the national interest and shows signs of taking action, then it would lead to international applause for the opposition."

Possible rejection

The lower house in Japan’s parliament can override a rejection to the bill by the upper house, but the opposition has threatened a censure motion against Fukuda's government should that occur.

The LDP has warned the opposition of a snap general election if it pushes through a censure motion.

The opposition took control of the upper house in July in a voter backlash over scandals in the government of Shinzo Abe, the former prime minister.

Robert Gates, US defence secretary, called on Japan to resume the mission during a visit to Tokyo.

He said Japan should play a role befitting "one of the world's greatest and wealthiest democracies".

Japan has been officially pacifist since the end of World War II, making all of its military operations overseas controversial at home.