The lawsuit was brought by owners James and Tasios Bovis against Handlery Hotels, which has leased the commercial space to the Bovises since 1966.
The move aims to save the bar from being demolished to make way for a new tenant that wants both an adjacent two-floor retail space at 301 Geary St. and the space housing the bar at 247 Powell St.
The bar's owners were presented with an eviction notice that will force it to vacate March 10, and a grassroots movement to save the landmark bar has been growing since news of the eviction broke in early January.
The building's landlord, Jon Handlery, whose family has owned the property since the 1950s and has leased the space to The Gold Dust Lounge for its entire operation, says that he has been open with the Bovises about his search for a tenant for the larger retail space since the last retailer, Casual Corner, moved out in 2006.
A clause in the bar's lease allows for the building owners to terminate the lease with 90 days' notice, and Handlery said that he has made sure the Bovises were aware of the clause when they resigned their lease every three years.
The lease came up for renewal in December, which is when Handlery said he told the Bovises that there was a strong chance a new tenant would want the space.
The lawsuit alleges that the Bovises unknowingly signed an amendment to their lease and that, because of the Bovises "advanced age" that the misrepresentation constitutes financial elder abuse.
At a news conference this afternoon, the Bovis' attorney Joseph Cotchett said the Handlery family used "trickery and deceit" to get the Bovises -- both of whom are in their 80s -- to sign leases that had been amended without their knowledge.
"Under California law, you can't do that to senior citizens," Cotchett said. "You can't take advantage of senior citizens."
The lawsuit alleges that representatives for the Handlery family gradually snuck in a shorter and shorter lease termination clause while telling the Bovises they were signing an amendment with no material changes.
The building owners want the Gold Dust Lounge to make way for higher paying tenants that they refuse to name, Cotchett said.
"They won't say. They won't tell us what they want to turn it into," he said. "This is really all about greed."
The spokesman for the Handlery family, Sam Singer, called the lawsuit "straight from 'The Twilight Zone'" and "an irresponsible abuse of the judicial system" for its alleged lack of merit.
"Their time would be better spent searching for a new home for the Gold Dust rather than filing fictitious lawsuits," Singer said.
The retail space was partitioned in 1965 into the bar space and the adjacent, larger retail space -- the Elkan Gunst Building, which has been designated a significant landmark, or point of interest.
According to Handlery, the incoming tenant wants the entire first floor and basement, which would encompass the bar and the art gallery.
Three weeks ago, a contingent of the bar's supporters made a presentation before the city's Historic Preservation Commission in an effort to gain support for classifying the Union Square lounge as a historic landmark.
Since it first became a bar in 1918, the Gold Dust Lounge has been host to "the people who made San Francisco what it is today," Cotchett said.
In the 1960s, Bing Crosby was part owner of a burlesque at the property called "Bustles and Beaus." Crosby's business partner commissioned the frescoes of half-naked women and cherubs on the ceiling that can still be seen today, Cotchett said.
The lawsuit alleges that famed newspaper columnist Herb Caen used to frequent the Gold Dust Lounge, along with Tony Bennett, Janis Joplin, Rosemary Clooney, Fats Domino and several former mayors, including George Moscone and Willie Brown.
The Bovises and their representatives have received "literally hundreds of phone calls" from Gold Dust patrons and supporters who want to preserve the San Francisco watering hole and the unique character of the "cable car corridor" along Powell Street, Cotchett said.
He encouraged anyone who wants to support the effort to save the Gold Dust to contact the office of Supervisor Jane Kim, whose District 6 includes the business.
Singer called the attempt to classify the bar as a landmark "a mockery of historic preservation."
Singer said the bar lacks architectural significance and that "it cannot be sufficient that a bar is an example of an 'American' cocktail lounge of the mid-twentieth century," as the bar owners described it in their presentation to the commission.
"There is no scarcity of those," Singer said.
