Saddled with an annual fuel bill of about ¥3.1 million, potato farmer Katsuhiro Yamamoto, like many others who work the soil for a living, is keeping a nervous watch on lawmakers in Tokyo as they battle over the extension of higher gas tax rates.

The two cars, five trucks and five tractors Yamamoto operates on his farm in the central Hokkaido village of Nakasatsunai soak up about 10 percent of his business expenses.

Special laws on auto-related taxes are set to expire at the end of the month, but the political wrangling will not die with them.