Prime Minister Yoshihiko Noda risks sparking the deepest split in his party since taking office two months ago as he determines whether to join trade talks led by the U.S., Japan's No. 2 export destination, on the Trans-Pacific Partnership free-trade agreement.
Noda, who last week responded to exporters' concern over the yen's strength with what might have been the biggest currency intervention on record, set a deadline of this week for proceeding with the TPP talks.
The TPP would slash tariffs like Japan's 778 percent duty on rice and open competition in industries including pharmaceuticals, stirring the opposition of about half of the lawmakers in the ruling Democratic Party of Japan.