With Prime Minister Shinzo Abe increasingly bent on altering the pacifist Constitution, backers and foes of his revisionist agenda held gatherings on Constitution Day on Saturday to make their voices heard.

Opponents massed at a hall in central Tokyo to unify their argument against the constitutional revisions being pushed by the Abe administration.

"We are in a situation where pacifism, which is the foundation of the Constitution, is at unprecedented risk," said Ken Takada, who helped organize the gathering at Hibiya Public Hall in Chiyoda Ward.