SAN FRANCISCO (KPIX) — A dispute is heating up over a proposed requirement to place 32″ x 24″ posters displaying the words “Black Lives Matter” at all San Francisco police stations.

Each police station would be required to place the signs in a public area so that anyone entering the building could see them. but that’s not sitting well with the rank-and-file police union.

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“I can speak on behalf of the command staff and members of this department. Black lives do matter and they matter to this police department,” said San Francisco police chief Bill Scott.

But in a letter sent to the Police Commission which voted Wednesday unanimously to mandate the signs, the San Francisco Police Officers Association which represents more than 2,000 officers said in part the “directive that the San Francisco Police Department prominently display posters in support of that same political organization, establishes a new precedent that raises concerns about introducing political agendas.”

“What we are talking about here is not about the Black Lives Matter organization or entity,” said San Francisco Police Commission vice president Damali Taylor.

Taylor is one of five commissioners appointed by the mayor and the board of supervisors.

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“We are talking about an expression of values that Black lives matter to the San Francisco police department,” Taylor said.

Tony Montoya, head of the SFPOA, said he was unavailable for an on-camera interview but issued this statement reading in part, “The Police Commission should put away their soap boxes and stop their political grandstanding … It’s time for the commissioners to get beyond hashtags, posters and politics.”

“This is not at the expense or in lieu of anybody or anyone else’s life. That’s not what this is about,” chief Scott said.

The posters will have to be on display within 30 days.

“We will support and are fully committed to implementing this resolution,” Scott said.

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The SFPOA doesn’t support the posters being displayed but added, “Make no mistake about it, the SFPOA supports the notion that all black and brown lives matter.”