Restaurant owners sue New York City, hoping to block its ‘ridiculous’ vaccine mandate.

A group of small businesses is suing New York City, hoping to stop the city’s first-in-the-nation vaccine mandate for restaurants, gyms and other indoor public venues.

The lawsuit, filed on Tuesday in Richmond County Supreme Court, has the support of prominent Republican elected officials, including Representative Nicole Malliotakis and Joe Borelli, a City Council member; both represent Staten Island.

The city is requiring patrons and employees of restaurants and certain other businesses to show proof of vaccination. The plaintiffs say the city is unfairly targeting businesses that are struggling during the pandemic, and that there should be exemptions for people with certain medical conditions or religious beliefs.

Mayor Bill de Blasio has argued that the vaccine mandate and other measures are needed to curtail a troubling rise in coronavirus cases, driven in part by the more contagious Delta variant, and to encourage more New Yorkers to get vaccinated. New cases in the city have surged to an average of more than 1,700 a day, from about 250 a day in early July. About 68 percent of adult residents in the city are fully vaccinated.

The city’s vaccine mandate took effect on Tuesday, and applies to a variety of businesses.

“The executive order has rendered it impossible for anyone who chooses not to be vaccinated, for whatever reason, to work in the designated industries, wholly depriving them of their livelihood,” the lawsuit says.

Andrew Giuliani, a Republican who is running for governor, said he supported the lawsuit and that businesses should be able to set their own rules.

The plaintiffs include Deluca’s Italian Restaurant in Staten Island, Pasticceria Rocco in Brooklyn andStaten Island Judo Jujitsu.

New York City’s mandate is similar to one approved in France last month that prompted large protests. Enforcement by city health officials will not start in New York until Sept. 13, the day when the city’s public schools are expected to reopen.

The lawsuit argues that the mandate unfairly applies to restaurants but not other indoor locations like hair salons, office buildings or houses of worship. Republicans also say the rules are too challenging for small businesses to enforce.

“It is beyond ridiculous that the government is mandating these already struggling small business owners to be the city’s ‘vaccine police,’” Ms. Malliotakis said in a statement.

Mr. de Blasio said on Wednesday that he was confident that his executive order would withstand a legal challenge.

“I’ve had the conversation with the Law Department — tremendous confidence that we’re in a very strong legal position,” Mr. de Blasio said. “We’re in a global pandemic still. The decisions that have been taken have been taken with the leadership of our health officials who have been fighting this battle from the beginning.”