of a string of national holidays, despite scuffles in parliament as opposition lawmakers tried to stop a vote on the issue. The return of the unpopular 25.1 yen (24.1 U.S. cents) a litre tax on gasoline halfway through Golden Week holidays, when many families take to the road, comes amid rumblings within the ruling coalition that Prime Minister Yasuo Fukuda should quit.
Surveys show his popular support has already sagged to below 30 percent as voters fret about rising food and fuel prices and a slowing economy.
Fukuda said restoring the tax had been a difficult decision but that losing the annual 2.6 trillion yen (US$25 billion) revenue from the tax would pinch the government's hard-pressed budget.
"Is it alright to have a shortage in revenues when there are calls for improvements in social welfare such as medical care and steps to deal with the falling birthrate?" he said in a nationally televised news conference.
Angered by the ruling bloc's decision to force through the bill restoring the tax, opposition lawmakers crowded parliament waving placards reading "abuse of power" and "end roads waste".
They tried to blockade the speaker of parliament's lower house from the chamber, forcing him to wrestle his way through with the help of security officials an hour later to get the vote passed.
Across the country, lines of cars formed at petrol stations ahead of the move as drivers took advantage of the lower prices during Golden Week -- a string of three national holidays spread over a week.
Tempers frayed at one petrol station near Osaka, where a man was arrested for threatening another driver after jumping a fuel queue on Tuesday, the Mainichi Shimbun newspaper reported.
Aggravating the issue, record global oil prices mean the price of petrol will likely jump 30 yen after the tax returns.
"I only drive on the weekend, but I went and filled up quickly," said Kazuhiko Uchida, 41, who works in manufacturing.
"People are dissatisfied with politics that leaves them out," he said. "I feel I don't know what they are doing, or for whom."
The tax row, along with unpopular revisions to medical insurance for the elderly and a long-running scandal over pensions, helped the opposition win a by-election in southwestern Japan on Sunday, underlining the pressure on the prime minister.
"His days are numbered, no matter what," said Koichi Nakano of Sophia University. "For now there is no clear successor for the job, but I think people will be looking at poll figures after this unpopular move."
The petrol price fell when a three-decade old "temporary" tax lapsed at the end of March because of a stalemate in parliament.
Opposition groups, led by the main opposition Democratic Party, stalled the issue in parliament's upper house, which they control. The government can push through a bill in parliament's more powerful lower house after 60 days, which has now passed.
The opposition, which is pushing for an early election, says a tax earmarked for road building is wasteful.
"The public knows that the 2.6 trillion yen tax increase won't be used for them, but that it'll be used for the interests of the (ruling parties)," Naoto Kan, a senior lawmaker of the main opposition Democratic Party, told reporters.
