Reacting to news of a lawsuit that threatens to drive out the Port of Charleston’s top cruise customer, city and maritime leaders promised to head to court in support of Carnival Cruise Lines and mocked the arguments against the company’s business.

Neighborhood, preservation and environmentalist groups filed a lawsuit today against Carnival in the ongoing dispute over cruise ships calling in Charleston, while city and port officials announced plans to join the battle on the side of the cruise company. The civil suit, being brought by the Coastal Conservation League, the Preservation Society of Charleston, and the city’s Ansonborough and Charlestowne neighborhoods, asks the court to find Carnival’s use of the Union Pier Terminal illegal.

Blan Holman, an attorney with the Southern Environmental Law Center, said Carnival’s current operations — its ship Fantasy is homeported in Charleston — is causing health and environmental problems.

“We don’t think there’s ever been a lawsuit filed like this against this industry,” he said. “If there’s any place in the United States where this should get challenged and resolved, it’s Charleston.”

Flanked by two dozen port, political and business leaders, Charleston Mayor Joe Riley repeatedly called the lawsuit “abusive” at a news conference at City Hall shortly after the lawsuit’s filing. He also said the idea of challenging whether a ship could dock at the port “requires some creativity.”

“We’re going to beat them, and we’re going to stop this kind of foolishness in our city,” Riley said, as cruise ship supporters applauded. The State Ports authority also plans to intervene in the lawsuit, and the International Longshoreman’s Association will vote tonight on whether the union will also intervene.

S.C. Gov. Nikki Haley issued a statement this afternoon thanking Carnival for its local business and for “bringing so much to the businesses and vendors of the area by filling restaurants and stores and turning the economy — and by exposing a new crop of visitors Charleston’s beauty, history, and southern charm.”

The lawsuit against the Panama-based business is the most recent development in a 1 1/2-year-long saga between the city, the state ports, Carnival and the city’s active residential and preservation groups.

At issue is how to foster the growing cruise ship industry as a part of the city’s tourism picture while managing its ill effects — much like city regulations manage ill effects from horse carriages, tour buses and hotel projects.

Last fall, the city and Ports Authority have agreed to capping the ships at no more than one at a time or 104 visits per year, but the agreement is not legally binding.

Residents claim it offers them no assurance that the number of cruise ship visits — which already have grown from 33 to 67 to 90 during the past three years —won’t continue to climb.

Coastal Conservation League executive director Dana Beach said no one likes the idea of filing a lawsuit.

“We reached a point where there is no alternative left,” he said.

Beach noted 28 cruise ships are currently being built to serve 5,000 or more passengers and that the cruise volume internationally has risen from 2.5 million passengers in 1999 to 12 million last year.

“Everybody is planning for more,” Beach said. “All of the facts and evidence suggests... the continuing growth of the industry. Our concern is not what is going on but what could happen over the next decade.”

Beach also said the State Ports Authority’s prime motive is to maximize commerce and revenue from the waterfront — its top executives are given bonus payments based on volume and revenues.

“The only thing you can trust (Ports Authority executive director) Jim Newsome for is to represent the best interests of the agency he has,” Beach said. “We don’t hold him at fault for doing that.”

Randy Pelzer of the Charlestowne neighborhood noted the 1,800-foot-long berth planned at the Port Authority’s new passenger terminal would be large enough to hold two ships the size of the Carnival Fantasy.

Carrie Agnew, an Ansonborough resident, said the cruise ship’s salsa music once was turned up so loud she could hear it inside her home with her windows and doors shut. “I called the police one afternoon because it was so loud,” she said. “I couldn’t get away from it.”

She said she also is concerned about smoke and soot from the ships while they’re in port. “To be breathing this is scary,” she said. “It’s bad enough to see it. ... My concern is people will stop wanting to live here, stop wanting to come here.”

One question the lawsuit raises is whether Carnival’s Fantasy violates the city’s intricate zoning laws, including one that puts the limit on size and locations for new hotels. Holman said the Fantasy “is twice as large as the largest hotel in Charleston. You could not build a building like that there.”

Beach said residential and environmental groups were unable to muster enough votes on City Council because too many council members felt that the city didn’t have jurisdiction.

Win or lose, Beach said the lawsuit will result in a legal ruling about whether those concerns are valid.

“It will be positive,” he said. “It will clarify a lot of issues that are cloudy right now.”