If Japan ever calls a referendum on whether to revise the postwar Constitution, it could spark a heated TV advertising war, akin to what the U.S. goes through for its presidential election campaigns.

The national referendum law as it now stands in principle enables anyone for and against constitutional amendment — Prime Minister Shinzo Abe's longtime goal — to freely invest in advertising, broadcast or print, as a way to get their message across.

But this freedom is now under scrutiny. Critics say the more robustly funded pro-revision camp led by Abe's ruling Liberal Democratic Party will inevitably gain the upper hand in this unregulated war of advertising, unleashing TV commercials with the force and frequency that its opponents can never match.