Japan took the first major step Monday toward rewriting its post-World War II pacifist constitution, a top priority for the conservative premier as the country seeks to carve out a larger global role.
Parliament approved a bill outlining procedures for a referendum on the first revision of the US-imposed 1947 text, which says Japan forever renounces the right to wage war.
Prime Minister Shinzo Abe, an outspoken conservative and the first Japanese leader born after World War II, has made rewriting the constitution one of his top policy goals.
He pledged to campaign on constitutional reform in nationwide elections in July for the upper house of parliament.
"In the next upper house election, we want to tell the voters that the LDP has been working on a draft outline of a new constitution," Abe said, referring to his Liberal Democratic Party.
He thanked members of parliament, saying they had "proved to be responsible by approving the legislation."
Japan already has one of the world's best-funded armed forces but calls them the "Self-Defence Forces."
Abe says Japan should have a full-fledged military to allow it to assume a greater global role, including participating in peacekeeping operations abroad and cooperation with the United States.
The bill, which says a new constitution needs to be approved by a majority of voters, passed the upper house Monday after clearing the lower house last month.
Some 200 pacifist and left-wing activists rallied in front of parliament, chanting, "Don't change the constitution for the worse!"
Opinion polls have shown that the Japanese public support the general idea of amending the constitution, although most voters also want the country to remain officially pacifist.
Kazuo Shii, chief of the Japan Communist Party, vowed to fight the revision.
"We will strongly protest against this outrage," he said.
The main opposition Democratic Party supports a revision, but voted against the legislation, saying a referendum should not be only about rewriting but also other issues facing Japan.
Abe has "no vision of what position Japan will have in the international community," Ichiro Ozawa, leader of the Democratic Party, said Sunday.
"He is just talking about a vague idea of cooperation with the United States."
The legislation says the referendum cannot take place before 2010, during which time the ruling party will work on a new draft.
"We didn't have rules on how to amend the constitution," chief government spokesman Yasuhisa Shiozaki said. "What is important is that the debate on the constitution will become more active."
Constitutional revision could also rouse opposition in neighbouring countries which remain suspicious of Japan due to its wartime aggression.
But Abe has worked to repair ties with China and South Korea, and neither country protested when his government upgraded the post-WWII "Defence Agency" to a full defence ministry in January.
The prime minister says the government can also simply change its interpretation of the constitution before the revision to allow "collective self-defence" -- or the use of force to counter an attack on an ally.
Before heading to the United States last month, Abe appointed a panel to assess the notion of collective self-defence.
One question the experts will consider is whether Japan could shoot down a North Korean missile heading over its territory to the United States -- an action forbidden under the current interpretation.
