Remember when Bill de Blasio, the People’s Mayor and not at all one of those imperious out-of-touch/out-of-town billionaires, promised a new era of transparency in city government?

Now that he’s in charge, he’s about as transparent as oak.

This week the Press Club of New York blasted de Blasio in an open letter that said, “You have departed from a precedent set by at least eight mayors before you, which has been to take questions in open press conferences without restriction as to the subject matter.”

That doesn’t sound like the Billy Blazes we were promised.

“I will increase transparency with a series of reforms of the Freedom of Information Law,” candidate de Blasio told the New York City Bar in an interview published in 2013.

“I will include FOIL [Freedom of Information Law] statistics in the Mayor’s Management Report . . . I will also levy fines and penalties against city agencies that regularly duck and delay FOIL requests, and proactively post online information that is most-frequently sought by FOIL request . . . I have continued to go beyond the current laws when it comes to transparency and disclosure and will continue these practices when Mayor.”

These days, though, de Blasio has established an alarming habit of walling off reporters from his public appearances. By May he had already logged 83 events at which journalist access was restricted or barred.

At press conferences, he bristles when asked a question he doesn’t want to answer, telling the hacks that they’ve gone “off topic,” a phrase de Blasio evidently hopes sounds less self-incriminating than “no comment.”

The trick is this: de Blasio holds a presser, warns everyone to stay on topic, then answers questions on anything that comes up. Until he is presented with a question he doesn’t like: Then he swats it away for being “off topic.”

Meanwhile, the unanswered FOIL requests are piling up.

Asked about burying FOIL requests he promised to treat as lovingly as a mom does her kid’s crayon portraits, de Blasio told Capital New York, “I’m no lawyer.”

The buck stops . . . over there. Go talk to my general counsel. And what did he say?

“Most of us favor transparency in the abstract,” Zachary Carter told Capital New York.

Concrete transparency might actually involve giving up information that could hurt his boss. Which is exactly why we have freedom of information laws in the first place: accountability. People who purport to be doing the public’s business prefer to do so secretly.

Capital New York published this priceless summation of Hizzoner’s new tune on FOIL: “The de Blasio administration said no records would be turned over under the FOIL law, which protects certain government records from being disclosed, like some ‘intra-agency communications’ and ‘instructions to staff that affect the public.’ ”

Those are some pretty big asterisks. It’s like you bought a jar of vitamins and discovered the fine print read, “may cause jaundice, heart palpitations, projectile vomiting and irreversible brain damage.”

De Blasio’s campaign vow, “I will increase transparency with a series of reforms of the Freedom of Information Law” meant, “I will strangle transparency until the little monster is gasping for air, suckers. Now let’s get back to me giving meaningless crowd-pleasing speeches about inequality!”

As Mayor, de Blasio has gotten a little more sophisticated. He sounded like Slick Willie II when he told the New York Observer, “I believe deeply in transparency. By definition it is in the eye of the beholder. We believe there is a whole swath of information that needs to be available to the public [if it] . . . is appropriately disclosable.”

Amusingly enough, de Blasio’s previous gig was public advocate, which despite being a small-to-irrelevant office did successfully produce a lot of verbiage — much of it about transparency.

Last April, for instance, Public Advocate de Blasio trotted out a “Transparency Report Card,” discovering “many agencies have failed to obey the law and make records public. At the NYPD and Housing Authority, which both received an ‘F’ rating on the report card, nearly a third of Freedom of Information requests went altogether unanswered. Across all agencies, one in ten requests to the fell through the cracks — a clear breach of Freedom of Information Law.”

All year long, de Blasio’s NYPD has been charged with stonewalling FOIL requests. In February, an NYPD official wrote to a Gothamist reporter that he was unable even to provide a copy of the department’s FOIL handbook, citing attorney-client privilege.

De Blasio is merely borrowing from his idol, President Obama, who famously promised to deliver the “most transparent administration in history.” That promise has so been so belied by Obama’s information-restricting White House that it prompts “snickers . . . tipping toward outrage,” reported Politico.

Larry Seary, the president of the New York Press Club, might have been thinking of both men when he said in his open letter to de Blasio, “It is sad that a man who deems himself a progressive, is retrogressive — when freedom of the press is at stake.”