The union might file suit before the end of the year, said Richard C. Iannuzzi, president of New York State United Teachers. He said he is waiting for union lawyers to get their legal claim in the "right shape."
"We will go to court," Iannuzzi said. He said the union believes the requirement of a 60 percent "supermajority" to exceed the cap violates constitutional "one man, one vote" protections that give every person's vote the same weight.
Additionally, he said the spending caps -- coupled with the state's 2011-12 education spending cuts -- are making it difficult if not impossible for poor school districts to provide the "sound, basic education" they are obligated to under the state constitution.
"Obviously . . . [the law] has to be tested someplace," Iannuzzi said of the tax-cap law, arguably one of the two biggest legislative achievements of Gov. Andrew M. Cuomo's tenure. "It doesn't look like it's going to be tested in the Legislature, so I guess it'll have to be tested in the courts."
Passed in 2011, the property-tax cap dictates that school districts and local governments keep tax hikes below 2 percent (or the rate of inflation, whichever is lower) or obtain a 60 percent vote from government boards or school budget voters to exceed the cap. The legislation includes some offsets for pension costs and other items.
When he signed the cap into law, Cuomo said: "It's going to change the trajectory of this state."
Last spring, the first time the tax cap was in effect, 92 percent of school districts stayed within its limits, according to the Cuomo administration. The average tax hike, roughly 2 percent, was less than half of the average property-tax hike over the previous 10 years of 5.3 percent.
But school districts and activists' groups have said the cap has forced layoffs and service cuts that have hurt the quality of education -- especially in poorer districts.
"As we look at the impact of both the cuts in state aid and the property tax, the reality is that the wealth gap and the ability of poorer school districts to provide a sound basic education, whatever that means today, is much more difficult than it has been in the past -- and much more difficult than it is for wealthier districts," Iannuzzi said. "So, just on its face, what's the reason for that? And is it the property tax cap, and is it the way we fund education?"
A Cuomo spokesman said taxpayers wouldn't want to turn back the clock. "Governor Cuomo's tax cap has been an unqualified success," said Rich Azzopardi. "Taxpayers simply can't afford to go back to the bad old days and have New York continue to spend more money per student than any other state . . . "