A long list of top-flight celebrities are headlining a fundraiser planned in New York next month to benefit the campaign for same-sex marriage in Maryland.

Cast member Julianne Moore answers a question during the panel for the HBO film "Game Change" at the Television Critics Association winter press tour in Pasadena, Calif. in January. (Mario Anzuoni — Reuters)

Barbara Bush, daughter of the former president, is also scheduled to attend, along with Maryland Gov. Martin O’Malley (D) and about two dozen other same-sex marriage advocates from the worlds of sports, fashion, movies and television.

The Sept. 13 event, for which tickets range from $250 to $25,000, is booked atop The James hotel, which promises “a sexy social atmosphere, with an enclosed bar and lounge set against 360-degree views of the Manhattan skyline,” according to its Web site.

The fundraiser for Marylanders for Marriage Equality comes as both sides gear up for a more visible campaign heading into November. A same-sex marriage law was passed by the Maryland legislature in March but easily petitioned to the ballot by opponents of the measure.

Same-sex marriage is already legal in New York. Several of the celebrities scheduled to attend next month’s benefit for Maryland appeared in a New York ad campaign that served as a model for one in the Free State during its legislative debate.

They include Bush and Moore, as well as professional hockey player Sean Avery and hip-hop mogul Russell Simmons.

Several of the celebrities have Maryland connections, including Ken Mehlman, the former chairman of the National Republican Committee who came out as gay in 2010; film maker John Waters, a Baltimore native; and Hilary Rhoda, a model who was born in Chevy Chase.