NEW YORK – The United Federation of Teachers’ decision to sponsor Rev. Al Sharpton’s upcoming anti-police protest in New York City is a disgrace.

That’s the message Patrolmen’s Benevolent Association President Pat Lynch made clear in a recent open letter to the New York Post, taking the unusual step of publicly chastising a labor ally instead of resolving the conflict quietly through the city’s Central Labor Council.

Sharpton’s “March for Justice for Victims of Police Brutality” is purportedly aimed at raising awareness of police brutality. Sharpton and his left-wing supporters are capitalizing on the cases of Missouri teen Michael Brown, an unarmed black teenager who was fatally shot by a St. Louis police officer, and Eric Garner, a 43-year-old Port Richmond resident who died in police custody last month.

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But Lynch and other NYC law enforcement officials believe “it is absolutely ridiculous that (Mulgrew) … would waste his members’ dues to get involved with a march that has nothing to do with teachers or his union,” Lynch wrote to the Post.

The police union boss pointed out an array of problems facing the UFT – from battles over charter schools to challenges to teacher tenure – as more disserving of the union’s attention.

“Mulgrew knows that the UFT is under siege from all sides, and this is purely an attempt to distract attention from that mounting criticism,” Lynch wrote. “How would he like it if police officers lined up with the activists who oppose his efforts to shield bad teachers and undermine effective charter schools?”

Lynch told the Post the PBA has “never had a problem” with the UFT, and is unsure why Mulgrew is suddenly bad-mouthing police.

But what is clear, Lynch wrote, is that the UFT boss is more focused on “continuing to curry favor with politicians and Al Sharpton” than issues facing his 200,000 members or the city’s 1.1 million schoolchildren, according to the Post.

“We typically boost each other up. I’m dumbfounded why Mike Mulgrew would do and say the things he has,” Lynch told the Post. “It’s disgraceful.”

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Other police officials were less surprised.

“Teachers union leadership marched alongside Sharpton, with the Bloods and Crypts, during the Bell case,” Detectives’ Endowment Association President Michael Palladino told the Post. “I imagine most educators would be embarrassed by Mulgrew’s actions.”

Many of them certainly are.

Some are so upset, in fact, that they’ve started a petition on Change.org calling for Mulgrew to resign for his humiliating behavior. Diane Morton-Gauttullo, a paraprofessional at PS 29, started the petition, which has garnered well over 1,000 signatures in a few short days.

“President Mulgrew does not represent my beliefs or me as a UFT member. Mulgrew is dragging me UNWILLINGLY into the current racial and police issues and aligning me with Rev. Sharpton!” the petition reads. “I am an educator not an activist and I serve the needs of all students. Shame on you Mulgrew.”

Numerous petition supporters shared their reason for joining the movement to oust Mulgrew in the comments section.

“I am disgraced to be associated with a racist like Al Sharpton! He is only about creating adversity. There is so much more to this incident and this rally is only going to cause more issues!” wrote Christina McNeice, of Brooklyn. “Our union should be supporting the NYPD at this time. We continue to see negative press about teachers and expect our fellow city unions to support us. How dare you Mr. Mulgrew align us with the likes of Al Sharpton!”

“Al Sharpton is a racist con artist,” according to Brooklyn resident John Dreher. “You’ll notice that he only shows up when a newsworthy incident occurs, that can put him in the spotlight. Have you ever heard of anything beneficial that he’s done to better black communities from ‘behind the scenes?’

“Of course not … he is a con artist, and a race baiter, who has ZERO credibility based on his past record. And now Mulgrew aligns himself with this man. Michael Mulgrew you now have ZERO credibility as well. Do the right thing and resign, you do not have the best interests of your members, and more importantly the children of this city, in mind.”