Fishermen and farmers in Japan may face higher oil taxes if Prime Minister Yasuo Fukuda's government fails to extend an exemption that expires March 31.

The 30-year-old law gives fishery and agricultural businesses a tax break totaling ¥3.8 billion a year, Takanobu Yasunaga, deputy director of the refining division at the trade ministry, said Wednesday.

The industries consume 1.9 million kiloliters, or about 12 million barrels, of diesel oil annually, according to the trade ministry.