A war of words between the ruling and opposition camps over political funding is expected when the extraordinary Diet session kicks off Tuesday.

The gloves will likely come off as the two sides debate revisions to the Political Funds Control Law following a scandal in which a 100 million yen donation from the Japan Dental Association was not properly reported by its recipient, the Liberal Democratic Party's largest faction, then headed by former Prime Minister Ryutaro Hashimoto.

The Democratic Party of Japan has called on the other opposition parties -- the Japanese Communist Party and the Social Democratic Party -- to form a united front to address the donation scandal.