To legalize collective self-defense, revisions are being prepared in five bills aimed at altering the government's interpretation of the Constitution, a ruling party lawmaker said Tuesday during the Golden Week holidays.

Prime Minister Shinzo Abe's team initially wanted to revise more than 10 laws during the Diet's fall session. Due to the rift in the ruling coalition, however, it narrowed the laws down to the five needed to discuss ways to revise the Japan-U.S. defense cooperation guidelines, the officials said.

The revisions will be mentioned in a government policy to be drafted for approval by Abe's Cabinet.

New Komeito, the junior partner in the ruling coalition with Abe's Liberal Democratic Party, is against the move to legalize collective defense. New Komeito insists the revisions should be debated thoroughly until at least next year.

Abe is trying to alter the government's long-held interpretation of the Constitution, particularly war-renouncing Article 9, to allow the Self-Defense Forces to engage in collective self-defense, or coming to the defense of an ally under attack.

U.S. President Barack Obama welcomed the move in his recent visit to Tokyo, but Japan's other neighbors, especially China and South Korea, which tasted Japan's wartime brutality first-hand, are pushing against Abe's effort to win a more "proactive" security role for Japan.

Subject to the proposed revisions are the laws governing the SDF, which define Japan's response to military attack, and those concerning how to deal with contingencies in "areas surrounding Japan," ship inspection operations and U.N. peacekeeping operations.

At present, the role of the SDF is limited to purely defense, as stipulated by the Constitution.