The Constitutional Democratic Party of Japan (CDP) is showing signs of changing its position on the country's national security legislation, in an apparent shift toward realism to take the helm of the government.

The main opposition party has claimed that the security legislation, which allows Japan to exercise its right to collective self-defense, is partly unconstitutional.

However, former CDP leader Yukio Edano said at a meeting in the city of Saitama last week that there were "no unconstitutional parts" in the legislation so "there is no need to change it."