Groups for and against revision of the Constitution held rallies in Tokyo on Thursday to mark the 54th anniversary of the supreme law amid increasing calls for its revision from political leaders, including Prime Minister Junichiro Koizumi.

Leaders of the Japanese Communist Party and the Social Democratic Party stated firmly during a gathering at Hibiya Kokaido hall in Tokyo that the parties are determined to protect the current pacifist Constitution.

It was the first time leaders of the two leftwing parties appeared at the same gathering on Constitution Day, despite their similar positions on the nation's supreme charter.