Japan snap polls in December

The first jump in sales tax, which came into effect in April, knocked a tentative revival off course and was blamed for a sharp fall in Japan's second-quarter growth.

Commentators are coalescing around the idea that Abe will rule out a second rise, from eight percent to 10, and seek a popular mandate that would help him vanquish mumblings of discontent within his own Liberal Democratic Party and catch the still-battered opposition unprepared.

"Calling a , within this year is among my options," Abe told party bigwigs, the leading business daily Nikkei reported.

The LDP and its junior coalition party Komeito have begun preparations for a vote on either December 14 or 21, four other major national papers said.

Abe has been coy in public, telling reporters in Beijing yesterday he had made no decisions, although he admitted to a television interviewer last week: "When asked the question, a prime minister has a set formula: 'I'm not thinking of a snap election'".

Reports of an election come ahead of the release of the third quarter GDP data on Monday, which the government has for a long time said will inform the decision on pressing ahead with the sales tax hike scheduled to take effect in October next year.

The mass-circulation Yomiuri Shimbun was among media saying today that the rise would be delayed by 18 months to April 2017.

Last month's surprise inflation of the Bank of Japan's already-huge monetary easing programme, which sent a ripple of excitement through the markets and lit a rocket under stock prices, was also propitious.

The combined effect of this bounce and a feelgood delay in the tax rise would be a boon to Abe if he goes to the voters, and would strengthen his hand for difficult reforms, said Capital Economics in a note.

"A snap election could have the virtue of giving the government a stronger mandate as it struggles to push ahead with structural reform," it said.