A Japanese daily reports that Japan’s sovereign credit rating may be downgraded.

The Yomiuri Shimbun says credit rating firm R&I may lower the rating of Japan’s state bonds by one notch from the current highest level of triple-A.

R&I currently rates Japan, the U.S., Britain, Germany and France at the triple-A level.

The credit rating agency says it is considering the downgrade since the Japanese government is slow in reforming its taxation system to enhance fiscal health.

This is the first time that a Japanese credit rating company has considered downgrading the sovereign credit rating of Japan.