2075 scenario: The consumption tax is 17.1 percent just to keep the pension system afloat.

This is according to apparently leaked provisional calculations made by the Democratic Party of Japan-led government as part of pension reforms to get the top opposition forces, the Liberal Democratic Party and New Komeito, to discuss the tax hike bugbear.

The DPJ hopes to sell the public on phasing in consumption tax hikes until the levy is 10 percent by fiscal 2015 to meet the mounting social security costs of the graying and dwindling population.