The city is losing about $10 million per week on parking ticket revenue because of the NYPD work slowdown, according to budget watchdog estimates.

There were just 1,191 parking summonses handed out between Dec. 29 and Jan. 4 — down nearly 93 percent from the same period last year, when 16,008 of the dreaded orange envelopes were slapped on windshields.

Based on the weekly average ticket take of $10.5 million in fiscal 2014, the Citizens Budget Commission estimated the reduction could have bled about $10 million from city coffers.

And that doesn’t include other revenue losses from similar reductions in moving violations and court summonses during the slowdown, which is now in its third week.

“While losing $10-$11 million in a week is real money, in the context of the city’s $77 billion annual budget it’s a very small amount,” said Doug Turetsky, of the Independent Budget Office. “But if the losses continue over weeks and months, the effect on the budget becomes more substantial.”

Mayor de Blasio and Police Commissioner Bill Bratton have yet to confirm the work slowdown, saying they’ll do so after a detailed analysis.