Prince George’s County Executive Rushern L. Baker III (D) supports an amendment to state legislation that would likely require a private investor to spend in excess of $800 million to build a casino in his jurisdiction, a senior aide confirmed Monday.

Prince George’s County Executive Rushern L. Baker III in Annapolis last year. (Mark Gail — The Washington Post)

A bill that passed the Senate last week would authorize a sixth casino in Prince George’s and allow it and other Maryland slots venues to offer Las Vegas-style table games as well.

Baker has championed a “billion-dollar” facility at National Harbor, the 300-acre mixed-use development on the banks of the Potomac River. Other casino owners have questioned whether it is feasible to attract investors for such a high-end casino unless the state increases the share of slots proceeds the owner may keep.

The bill that passed the Senate does not alter an existing requirement that investors spend $25 million in “construction and related costs” for every 500 slot machines that will be located at the casino.

The change supported by Baker, according to an aide, would increase that requirement to $85 million per 500 machines for a Prince George’s facility. If the casino includes 4,750 slot machines — the maximum allowed at the site — the required investment would exceed $800 million.

While the amendment does not guarantee a “million-dollar” casino, it would ensure an upscale facility in keeping with Baker’s vision, said the aide, who spoke on condition of anonymity because he was not authorized to speak about the proposal.

With the legislature scheduled to adjourn in a week, the behind-the-scenes maneuvering on possible amendments comes amid a full-court press in Annapolis by Baker and his aides to bolster support for the bill.

Talking points being distributed to Prince George’s delegates Monday estimated the county would eventually receive $69 million a year in gaming and other tax revenues if a casino is built.

For illustration purposes, a handout said the revenue and job creation of a casino would match that of opening 10 Wegmans grocery stores simultaneously. According to the material, the annual revenue generated would be the equivalent to the cost of upgrading or replacing 59 fire engines operated by the county.

Clearly not all of Baker’s constituents are convinced of the merits of a casino.

In advance of a House hearing on the legislation Tuesday, a group of faith and community leaders plan to gather outside the State House to make their continued opposition known.

Meanwhile, Gary Loveman, the chairman, chief executive officer and president of Caesars Entertainment is planning to be in Annapolis on Tuesday, meeting with legislative leaders and news organizations.

Caesars is the only bidder for a casino in downtown Baltimore. Even though a Prince George’s facility would cut into the market of the Baltimore facility, Caesars has announced its support for the legislation.

Among other provisions, the bill increases the share of slots proceeds that operators may keep and allows them to keep all but 10 percent of table games proceeds.

The bill is staunchly opposed by the Cordish Cos., which is building a casino in Anne Arundel County that is scheduled to open in June.