An organization of cigarette sellers from the Seneca Nation of Indians has joined the court fight to have a new federal law declared unconstitutional.

The Seneca Fair Trade Association filed court papers with U. S. District Judge Richard J. Arcara on Thursday, asking him to strike down the law that bars the U. S. Postal Service from making commercial deliveries of cigarettes.

The group says it represents more than 140 businesses that depend on the Postal Service to deliver their tobacco products.

Daniel B. Moar, a lawyer for the group, asked Arcara to declare the Prevent All Cigarette Trafficking Act — commonly known as the PACT Act — unconstitutional.

“If the PACT Act is permitted to be enforced by the United States, hundreds of Senecaowned businesses will be forced to close their doors . . . resulting in a devastating impact to the Seneca Nation and the surrounding communities in Western New York,” Moar said in court papers. “Over 3,000 jobs will likely be lost.”

The law, designed to shut down the nation’s mail-order cigarette industry and stop Native American cigarette businesses from avoiding tax payments, took effect Tuesday. It was signed into law by President Obama in late March, after Congress passed it by a wide margin.

According to Seneca Nation business owners, many of the mail-order tobacco businesses run by tribe members already have shut down this week.

The group is following up on a lawsuit filed earlier in the week by Aaron Pierce, a Seneca cigarette seller, who also contends that the new law is unconstitutional.

Tuesday, Pierce’s lawsuit earned his business — Seneca Smokeshop.com — at least a two-week reprieve from enforcement of the law. Arcara issued a temporary restraining order stopping the government from enforcing the law against Pierce’s company only.

Legal arguments on the new constitutional challenge will be heard by Arcara today.