Blue Lives Matter NYC is filing a federal lawsuit against Mayor de Blasio and Transportation Commissioner Polly Trottenberg over not being allowed to paint a "Blue Lives Matter" mural.

The non-profit organization requested to use their own funds to paint a mural in front of One Police Plaza.

In a letter to the mayor, they pointed to him for allowing a "Black Lives Matter" mural to be painted along Fifth Avenue, outside Trump Tower.

They said they want a pro-police mural that would "honor the lives and memory of public servants whose heroic lives ended too soon."

A representative from City Law says they are unaware of the lawsuit but will review it when served with the papers.