City Councilman Jumaane Williams, one of the highest-profile foes of stop-and-frisk policing, now wants the NYPD to stop arresting people who commit “minor” crimes on the subway — because, he says, being arrested is “very disruptive” to the perps’ lives.

Williams’ Resolution No. 91 is nonbinding, but it calls on the police and MTA to “stop arresting people for committing minor infractions in the transit system.” Even if someone is known to be a habitual criminal, it specifies, the police should not arrest him or her for committing a “minor infraction,” because “an arrest can cause significant stress” to the criminal.

What crimes count as “minor”? Williams’ resolution says they include, “but are not limited to,” littering and occupying more than one seat. Hmm. Other infractions that the MTA groups in this category include: smoking, drinking alcohol, public urination, gambling and causing “annoyance, alarm or inconvenience to a reasonable person.”

Does Williams think transit cops should steer clear of cigarette smokers and public urinators and let screaming drunks get in the faces of their fellow commuters? Well, consider the apparent “wrong” he’s trying to right.

Since Commissioner Bill Bratton took over the NYPD, subway arrests have tripled over the same period a year ago. With stop-and-frisk problematic, it seems Bratton is ramping back up a tactic he pioneered in the early 1990s, as head of the MTA police.

Arresting fare-beaters and other miscreants wound up pulling in remarkable numbers of people with warrants for far more serious crimes. Murderers and rapists, it turned out, are much more likely than law-abiding folks to jump turnstiles. This shift in policing — from ignoring “minor” offenses to targeting them — was the start of the city’s historic gains against crime.

Which brings us to Councilman Williams, who sponsored laws to end bias-based profiling and to install an independent inspector general at the NYPD. Shouldn’t he be happy to see the police arresting real criminals?

After all, the argument against stop-and-frisk was that police were stopping people in high-crime areas just for behaving in what officers deemed a suspicious manner — which, critics charged, in effect meant that cops were stopping mostly young black and Latino men, most of whom weren’t doing anything wrong.

So if the police are instead arresting people who are actually committing crimes, what’s the concern?

According to Williams, arresting litterers, or people selling churros, or beggars, or “showtime” dancers, is “overly punitive and unfair” and can cause “financial hardship.”

His Resolution 91 also asserts that “many people believe that MTA rules are being enforced unfairly.” Yet every criminal busted in the act makes this complaint.

Consider this a sign of what’s next. Even if it passes, this nonbinding resolution wouldn’t force the NYPD to stop arresting subway troublemakers — but it’s surely a warning of more to come if Bratton doesn’t adjust.

Worse, it suggests that progressive legislators won’t stop with their victory over stop-and-frisk, that they in fact view any police enforcement of the laws as systemized bullying or harassment.

At least, Williams — fresh off his victories over the NYPD last year — appears to be testing the limits of how far the cops can be restrained from doing their job.

Many of us recall what it was like riding filthy, dangerous subways, where the most obnoxious New Yorkers felt free to terrorize their fellow riders. Do we really want to live in a city where the police are instructed to ignore actual criminal activity, because it is “stressful” when the criminals are arrested?

Seth Barron runs City Council Watch, an investigative Web site focusing on local New York City politics.