Metropolitan Park is a joint venture of Mets owner Steve Cohen and Hard Rock Entertainment. The concept calls for turning parking lots surrounding the ballpark into a mixed-use development and public park space.

The casino would sit near 126th Street in Willets Point, across from the Mets' stadium. But at a rally in Flushing Sunday, demonstrators said that Queens neighborhoods have come together to oppose the plan.

“It’ll bring displacement... congestion, traffic, gambling addiction. It’s absolutely not a good idea. Not a good bet for this city," said one woman who attended the demonstration outside the Queens Library.

The plan includes a 25-ace public park. A packet submitted for review by Queens Future, LLC, suggests the project would bring "new, job-creating commercial and entertainment uses." The backers also promise upgrades to the nearby MTA subway station.

However one opponent who spoke to NBC New York claimed Metropolitan Park is "a racist predatory project coming to the middle of working-class communities who are struggling.”

Those critics are calling on local leaders like State Sen. Jon Liu (D-Queens), who have supported the project to now fight against it.

In response, a Metropolitan Park spokesperson told News 4 in a statement, "The approvals from six out of six Community Boards, the City Council, State Legislature, and the entire Community Advisory Committee underscore the deep and broad community support for Metropolitan Park. We are committed to making this community-first vision a reality, delivering 23,000 union jobs, 25 acres of public park space, and over $1 billion in community benefits.”

Metropolitan Park is one of the final three projects bidding for a new casino license in New York City that is under consideration by the state. The other two finalists are Bally's in The Bronx, and a major expansion for Resorts World New York City near Kennedy Airport. The only finalist from outside the city was an MGM Resorts project in Yonkers, which was withdrawn in October. Rival bids, including a Jay-Z backed casino in Times Square, a casino near the United Nations and one in Coney Island, Brooklyn, were rejected by state-commissioned community advisory committees this year.

The state Gaming Facility Location Board expects to make decisions by Dec. 1, followed by Commission licensure by Dec. 31.