TOKYO (AP) -- Japan marked the 67th anniversary of its postwar constitution Saturday with growing debate over whether to revise the war-renouncing charter in line with Prime Minister Shinzo Abe's push for an expanded role for the military.

The ruling conservative party has long advocated revision but been unable to sway public opinion. Now Abe is proposing that the government reinterpret the constitution to give the military more prominence without having to win public approval for the revisions.

His push, backed by the U.S. which wants Japan to bear a greater burden of its own defense, has upset the liberals who see it as undermining the constitution and democratic processes.

Hundreds of people gathered at a Tokyo rally commemorating Constitution Day, a national holiday.

Japan's pacifist charter is at stake, organizer Ken Takada said: "We citizens must stand up, take action and raise our voice to stop Abe, or this country could return to a Japan that wages war with Asia as it has done before."

Written under U.S. direction after World War II, the 1947 constitution says the Japanese people "forever renounce war as a sovereign right of the nation" and that "land, sea and air forces, as well as other war potential, will never be maintained."

That ban has been relaxed over the years, with U.S. encouragement as the Cold War unfolded and America sought allies in Asia, allowing Japan to have a military to defend itself, dubbed a Self-Defense Force.

The ruling Liberal-Democratic Party has long denounced the postwar constitution as one imposed by the U.S., which occupied Japan from the end of World War II until 1952. Abe's grandfather and role model Nobusuke Kishi -- who was arrested as a suspected war criminal but never charged and later became prime minister -- was among vocal opponents of the constitution.

Abe advocates a "breakaway from the postwar regime" as a way to overcome the humiliation -- symbolically, the constitution -- as well as education system, social values and historical views set by the occupation.

A 2012 draft revision proposed by the Liberal Democratic Party promotes a conformist Japan and traditional patriarchal values, placing family units above individuals and elevates the emperor to head of state from the current "symbol." Civil liberties such as freedom of speech and expression can be restricted if considered harmful to public interest.

Official visits to Yasukuni Shrine, which enshrines war victims including convicted war criminals, would be legalized, and the war renouncing Article 9 of the constitution reduced to a mere policy, allowing a full-fledged military.

"Our goal is to write a new constitution of our own that envisions a new era and serves a new role," Yasuhiro Nakasone, a 96-year-old former prime minister who heads a group of lawmakers campaigning for a revision, said Thursday at a Tokyo gathering attended by hundreds of lawmakers, their supporters and business lobbies.

With potential military threats coming from China and North Korea, Abe wants to raise Japan's defense posture further, as well as allow the country to play a greater role in international peacekeeping.

Amending the constitution is a challenge, requiring two-thirds approval in both houses of parliament before they are put to a national referendum. Surveys show mixed opinions among Japanese to revising the constitution, with a majority disapproving and opposition growing amid escalating debate over what is seen as the Abe government's attempt to force through change by simply reinterpreting it.

Abe and other supporters of the change believe that Japan's current policy is inadequate. They say U.S. warships may come under attack while in or near Japan, or there may be instances in which Japanese troops have to fight for allies during international peacekeeping missions, even when Japan is not attacked directly.

To do that, Japan would have to exercise a right known as collective self-defense.

That would help strengthen deterrence in the Asia-Pacific and align with the direction of the U.S. strategy, Shigeru Ishiba, Liberal Democratic Party secretary-general and a defense expert, said in a speech in Washington this week.

"The lifting of the ban on the collective defense is basically taking any remaining meaning out of Article 9, so in that sense it's really going to be undermining the Constitution itself," said Koichi Nakano, a political science professor at Sophia University in Tokyo and an opponent of revision.

But Takeshi Iwaya, a senior lawmaker in charge of the ruling party's defense policy, said: "If we stick to this position, Japan won't be able to secure the necessary deterrence to defend our own national security or keep peace and stability in the region."

An Abe-appointed panel of defense experts is currently finalizing a recommendation to allow collective self-defense, expected in mid-May, which would pave the way for a Cabinet approval.

Whatever the reason, reinterpreting the constitution to change policies is inappropriate, because it could lead to abuse of power, says Tokyo company employee Rie Sato, 36. She said she hasn't seriously thought about the constitution, as it doesn't seem to directly affect her life.

"But I don't have any problem with the constitution either," Sato said while taking a lunch break outside an office building. "Perhaps I should give it a credit for my relatively peaceful life."