Mayor Bill de Blasio ordered city lawyers to stay silent about a groundbreaking lawsuit to keep bootleg cigarettes out of the Big Apple — because it came as Hizzoner was downplaying the illegal cigarette sales that led to the ill-fated police arrest of Eric Garner, The Post has learned.

The city Law Department drafted the civil racketeering suit the same week that a Staten Island grand jury did not indict NYPD cop Daniel Pantaleo in Garner’s chokehold death, and it was quietly filed in Brooklyn federal court on Dec. 9.

The Law Department drafted a press release boasting that the suit “is the first of its kind brought by the city against an out-of-state entity for supplying cigarette traffickers,” sources said.

But City Hall suppressed the news, ordering the Law Department not to put out the release, according to the sources.

The move kept de Blasio from looking like a hypocrite for cracking down on illegal tobacco sales at the same time he was minimizing Garner’s criminal activity, which led to his deadly July 17 arrest.

“Eric Garner was a decent man. Obviously, it was a minor offense he was committing — there’s no way it should have ended up in this situation,” de Blasio told HOT 97 radio on Dec. 4, a day after the grand jury ruling.

One city official said, “City Hall knew they had screwed up, so they squashed the press release.

“You can’t have the mayor blabbing away that selling loosies is a ‘minor offense,’ but then have the Law Department, which represents and protects the city and the mayor’s interests, file this suit,” the official said. “It reeks of duplicity.”

The official, citing de Blasio’s “Tale of Two Cities” campaign rhetoric, added that “the mayor has a problem with two cities, and he created it.”

“On one hand, to pander to his voting base, he spews some nonsense that selling loosies is a ‘minor offense,’” the official said.

“But, on the other hand, he realizes this is a major issue with serious ramifications if left unchecked and he has the city’s Law Department file this first-of-its-kind federal lawsuit against the smoke shop.”

According to a March report by Bloomberg News, an estimated 57 percent of the cigarettes smoked in New York are smuggled across state lines to avoid hefty state and city taxes that add $58.50 to the cost of a carton.

The city’s suit targets Discount Tobacco & Things of Woodbridge, Va., and its president, Gaby Nouhra, who are accused of conspiring to violate the federal Racketeer Influenced and Corrupt Organizations Act.

Court papers say the smoke shop, located in a suburban strip mall outside Richmond, is where alleged Staten Island bootlegger Michael Zekry bought more than 2,500 cartons of cigarettes that cops found in his van last month.

“Zekry had for at least the prior two years purchased similar quantities of cigarettes from DT&T, and made those purchases far more frequently than every 10 weeks,” according to the suit.

The suit seeks a court order barring DT&T from distributing cigarettes in New York, along with all illegal profits and unspecified damages, including three times the amount of tax money lost to the alleged trafficking scheme.

Nouhra didn’t return a request for comment.