A special committee of the House of Councilors approved a set of war-contingency bills Thursday, effectively guaranteeing the legislation's enactment at Friday's Upper House plenary session.

Committee members from the ruling coalition -- the Liberal Democratic Party, New Komeito and the New Conservative Party -- as well as from the Democratic Party of Japan and the Liberal Party, voted for the bills.

The ruling alliance and the DPJ had agreed on a set of amendments before jointly supporting the legislation in the Lower House last month.

Meanwhile, the Social Democratic Party and the Japanese Communist Party voted against the bills, stating that the legislation would violate the spirit of the nation's war-renouncing Constitution.

The bills are designed to ensure the smooth operation of the Self-Defense Forces in the event that Japan comes under attack. They also seek to bolster the central government's power over local governments in emergencies and boost the membership and role of the Security Council under the prime minister.

If enacted, the bills will represent the first such legislation for Japan since the end of World War II.

The government officially launched a study on legislation of this kind in 1977 -- but never acted on the results since the issue was regarded as a political taboo.