Coalition, allies of prime minister win majority of the seats in the upper house of parliament

Japanese Prime Minister Shinzo Abe, seeking to allay concerns he would divert energy from fixing a fragile economy to revising Japan's pacifist constitution after a big election win, said on Monday changing the charter would not be easy.

Abe's coalition and allies won two-thirds of the seats in parliament's upper house in Sunday's election. That victory, with the ruling bloc's super majority in the lower house, opens the door to revising the constitution for the first time since its adoption after Japan's defeat in World War II.

Abe said revising the constitution was his Liberal Democratic Party's cherished goal, but forging agreement on changes in the diverse pro-revision camp would not be easy.

Revisions require a two-thirds majority in both houses of parliament and a majority of votes in a public referendum.

"To realize revision of the constitution is my duty as LDP president," Abe said. "But it is not that easy, so I hope debate will deepen steadily."

Experts agreed that building such agreement would be tough.

"It's the first time to have two-thirds in both houses of parliament, but you can't find any issue on which the two-thirds can agree," said Gerry Curtis, professor emeritus at New York's Columbia University.

A stimulus package

Some in financial markets worry a focus on the constitution would drain attention from the economy, but Abe promised on Monday to craft a large stimulus package.

"A public referendum is needed so he must boost support to advance revision. So for constitutional change as well, he will probably come up with a large-scale economic package," said Daiji Aoki, senior economist at UBS Securities Japan.

Doubts about Abe's policies persist even though his ruling bloc won big in terms of the number of seats. Many voters felt they had no other option, given memories of the main opposition Democratic Party's rocky 2009-12 rule. Others stayed home.

Surveys show many Japanese voters are wary of changing the constitution's war-renouncing Article 9, which advocates see as the source of Japan's postwar peace and democracy. Conservatives see it as a symbol of humiliating defeat.

If taken literally, Article 9 bans the maintenance of armed forces. Successive governments have interpreted it to allow a military for self-defense, a concept Abe last year stretched to allow Japan's military to aid friendly nations under attack.

Formal revision of Article 9 would likely be largely symbolic - though nonetheless historic.

Convincing the Komeito party, the dovish junior partner in Abe's LDP-led coalition, to agree would be challenging. The pro-revision camp might therefore tackle another amendment first.

One possibility is a clause giving the government more power in a national emergency, a move critics say would curtail civil rights.

Another option, floated by the Komeito, would be to add an environmental protection clause. That less contentious step would nonetheless break the political taboo on revision.

It is unclear whether that would satisfy Abe's political base.

"Conservatives see the constitution as emasculating the nation," said Jeffrey Kingston, director of Asian studies at Temple University in Tokyo.

"If I'm in his camp, I'm thinking, this may be my best shot."