The S.C. Supreme Court heard arguments Thursday in two related lawsuits over Charleston zoning decisions that would allow a 10-story hotel on Marion Square, where the old county library now stands.

Both cases pit the city and the developer, Library Associates LLC, against the Historic Charleston Foundation and the Preservation Society, both of which believe the hotel is too tall for the site.

The court's ruling will decide if the hotel project can move forward as proposed.

In the first case, the city and developer are appealing Master In Equity Mikell Scarborough's ruling that City Council's rezoning of the site amounted to illegal spot zoning.

In the second case, the preservation groups are appealing Scarborough's ruling upholding the city's Board of Zoning Appeals decision to grant the developer a height variance.

Chip McSweeney, an attorney for the preservation groups, said his side argued that the two zoning decisions essentially violate the city's comprehensive plan.

Developer Michael Bennett has said the hotel's size is driven largely by its design as a full-sevice hotel, complete with a ballroom, meeting space, restaurants and shops.

Preservationists have argued that the 10-story hotel, while shorter than the nearby Francis Marion Hotel, would tower over nearby 18th and 19th century buildings.

The hotel project was first proposed in 2004.