The state United Teachers union is starting a $1.3 million statewide ad campaign opposing the cap on local and school property taxes.

The commercial — called “A Tax Cap Is Not The Answer” — began running this morning.

“Make no mistake, educators are taxpayers, too, and support real, meaningful tax relief,” union President Richard Iannuzzi said in a statement. “The agreement reached by the governor and Legislature fails to provide that relief. Instead, it would lead to the elimination of needed programs, even more overcrowded classrooms and thousands and thousands of additional layoffs. The impact on municipalities would cripple community colleges and prevent local governments from providing the essential public services that middle-class New Yorkers need.”

The ad quotes heavily from The New York Times editorial on the tentative cap agreement between Gov. Andrew Cuomo, Assembly Speaker Sheldon Silver and Senate Majority Leader Dean Skelos.

The new proposal, introduced in the Assembly, would still cap property taxes at 2 percent, but include some limited carve outs for pension growth and an undetermined expiration date.

Senate Republicans say the possible sunset date coinciding with rent control complicates the agreement, but remain confident a cap will stay in place.

The teachers union, long an opponent of caps, says pushing a ceiling the same year as deep cuts in education spending is especially troubling.