Differences within New Komeito mean Prime Minister Shinzo Abe's coalition partner may not back submitting a bill to legalize casinos during the current Diet session.

"I don't necessarily think we will reach consensus on submitting the bill to the current session and moving forward with it in the limited time we have," New Komeito chief Natsuo Yamaguchi said in an interview Monday in Tokyo.

A cross-party group of lawmakers has said it is preparing to submit the casino legalization bill to the Diet this session, which is scheduled to end Dec. 6. They hope this will boost tourism by leading to the development of "integrated resorts," with gambling alongside other kinds of entertainment.

While betting on horse, boat and bicycle races is allowed, casinos remain banned. Union Gaming Group estimates that Japan could turn into the world's second-largest gambling hub with $10 billion in annual revenue.

International gaming companies have been mulling billions of dollars in investment as Tokyo's selection to host the 2020 Olympics Games boosts confidence casinos will be legalized.

Yamaguchi said the public lacks "full understanding" of the casino issue and the potential harmful effects.