Lawyers for Mayor Bloomberg are asking a judge to ban any reference to the Second Amendment during the upcoming trial of a gun shop owner who was sued by the city. While trials are often tightly choreographed, with lawyers routinely instructed to not tell certain facts to a jury, a gag order on a section of the Constitution would be an oddity.

“Apparently Mayor Bloomberg has a problem with both the First and the Second amendments,” Lawrence Keane, the general counsel of a firearms industry association, the National Shooting Sports Foundation, said.

The trial, set to begin May 27, involves a Georgia gun shop, Adventure Outdoors, which the city alleges is responsible for a disproportionate number of the firearms recovered from criminals in New York City. The gun store’s owner, Jay Wallace, says his store abides by Georgia and federal regulations and takes steps to avoid selling firearms to gun traffickers. Mr. Wallace’s store is one of 27 out-of-state gun shops sued by New York City, and the first to go to trial.

City lawyers, in a motion filed Tuesday, asked the judge, Jack Weinstein of U.S. District Court in Brooklyn, to preclude the store’s lawyers from arguing that the suit infringed on any Second Amendment rights belonging to the gun store or its customers. In the motion, the lawyer for the city, Eric Proshansky, is also seeking a ban on “any references” to the amendment.

“Any references by counsel to the Second Amendment or analogous state constitutional provisions are likewise irrelevant,” the brief states.

Many Americans believe that the Second Amendment provides an individual the right to own a gun. Others believe that it provides no right to private gun ownership, but gives states the power to keep militias.

In a recent court deposition, Mayor Bloomberg said he believed “the Second Amendment of the Bill of Rights gives you the right to keep and bear arms.” But in a recent brief to the Supreme Court, lawyers for Mr. Bloomberg argued that the amendment “was not intended to vest armed power in citizens acting outside of any governmental military effort — either federal or state.”

In a statement sent via e-mail to The New York Sun, the city’s criminal justice coordinator, John Feinblatt, said the issue at the upcoming Adventure Outdoors trial “isn’t the Constitution but whether the respondents broke federal firearms laws.”

“The right to bear arms has nothing to do with whether the respondents made straw sales,” Mr. Feinblatt said.

A straw sale occurs when gun dealers sell to someone making the purchase on behalf of another — often someone with a felony record, who is ineligible to own guns. The city sent an undercover team to simulate a straw purchase at Adventure Outdoors. Lawyers for the gun store say the two hidden cameras brought in by investigators malfunctioned less than halfway into the purchase and fail to show the precautions taken by the sales staff at the store to prevent a straw purchase.

Of the city’s recent motion to preclude mention of the Second Amendment, a lawyer for Adventure Outdoors, John Renzulli, said, “If you can’t discuss the Bill of Rights in a court of law, where should we discuss these issues? Should we reserve it for the tavern?”

Mr. Renzulli said the city’s lawsuit did implicate the Second Amendment: “The politics involved here is whether the city has the power to go into another state and control the lawful sale of firearms.”

Still, Mr. Renzulli said he did not plan to oppose the city’s request regarding references to the Second Amendment. Mr. Renzulli, who has defended suits against the gun industry in Judge Weinstein’s courtroom before, said that in the past the defense has struck a deal with the plaintiffs on the matter: Lawyers for the gun industry won’t mention the Bill of Rights to the jury, if the plaintiffs don’t mention the National Rifle Association.

“We usually say we’re not talking about the Second Amendment and you’re not talking about the NRA as a huge lobbying group that controls the legislature,” Mr. Renzulli said.

He said he expected a similar agreement to be struck in the Adventure Outdoors case.