The Liberal Democratic Party's policy chief on Sunday called for changing the nation's pacifist Constitution after the ruling coalition won a landslide victory in the Upper House election.

Prime Minister Shinzo Abe's ruling coalition and like-minded parties appeared to win two-thirds "supermajority" needed to try to revise the post-war Constitution for the first time, some TV exit polls showed, although others only said it is within their grasp.

"Our party is one that calls for reforming the Constitution," said Tomomi Inada, policy chief of the ruling LDP, after the polls closed.

"Our party has already submitted a draft for reforming the Constitution," she added.

Revising the Constitution, especially the war-renouncing Article 9, has been Abe's long-term goal.

But the ruling LDP-Komeito coalition, in an apparent effort not to scare away voters, avoided highlighting the question during campaigning.