The government will find it difficult to pass a casino legalization bill in the Diet before its current session closes June 22, ruling coalition lawmaker Masakazu Hamachi said Saturday, raising concern that gambling resorts may have difficulty opening in time for the 2020 Tokyo Olympics.

Scheduling challenges will make approving the legislation hard, Hamachi, a representative from junior coalition ally New Komeito who sits on the committee set up to consider the bill, said in an interview in Tokyo.

The Liberal Democratic Party-led ruling camp, which has promoted casino resorts as a tourism-boosting complement to the 2020 Summer Games. Casino tycoons from Las Vegas Sands Corp. Chairman Sheldon Adelson, Wynn Resorts Ltd. Chairman Steve Wynn and Melco Crown Entertainment Ltd. co-Chairmen Lawrence Ho and James Packer have said they're prepared to spend billions on gambling resorts in Japan.