Passage of a controversial electoral reform bill Thursday has provided another example of the ruling coalition's increasing use of force that opposition lawmakers describe as as tyrannous.

During a Lower House plenary session Thursday, the ruling triumvirate -- the Liberal Democratic Party, New Komeito and the New Conservative Party -- passed their proposed revisions to the electoral system into law, putting an end to Diet deliberations on the issue.

A bill submitted as a counterproposal by the Democratic Party of Japan, the largest opposition force, was not even discussed.