Buffalo is "oversaturated" with charter schools, and the state should be more demanding when it is asked to create new charter schools here or to relicense existing ones, the president of New York State s teachers union said here Wednesday.

"I would say Buffalo has, unfortunately, more than reached a saturation point," said Richard Iannuzzi, president of New York State United Teachers. "It makes it almost a side-by-side school district, and you can t function like that."

He said the brakes should be put on charter school growth when total charter school enrollment exceeds from 5 to 8 percent of the enrollment of the traditional public school system in which the charters are located. In Buffalo, that figure exceeds 10 percent, and Albany has also passed that threshold.

The damage, Iannuzzi said, is that school districts are required to make transfer payments to charter schools based on enrollment and suffer financially as charter schools grow.

"I would hope that the chartering institutions [the state Board of Regents and the State University of New York] look much more carefully at the applications of charter schools in Buffalo and Albany," he told The Buffalo News Editorial Board.

When existing charter schools seek relicensing in those cities, "maybe you have to have a higher standard," Iannuzzi added.

Peter Murphy, a spokesman for the New York Charter Schools Association, said the State Legislature created that higher standard in 2007 by requiring new charters in Buffalo and Albany to present "significant educational benefits."

"That s a message from the Legislature that a higher bar is needed here," Murphy said.

NYSUT is aggressively seeking to unionize teachers at the state s 130 charter schools and already has 21 affiliates, including five in Buffalo.

Iannuzzi said the organizing efforts will separate charter schools with "a mission and a direction" from those with an "anti-labor, anti-union ideology."

Charter school teachers with union contracts generally have job protection safeguards that fall short of teacher tenure, he said.

Murphy said that NYSUT lobbied to cut charter school funding earlier this year and that its organizing campaign is "highly deceptive."

"He is about the adults," Murphy said. "He s about protecting them from consequences. That s what his job is."