With Success Academy CEO Eva Moskowitz reportedly in the running to become President-elect Donald Trump’s education secretary, the head of New York City’s teachers union is preparing for a fight.

“Let the fun begin,” said United Federation of Teachers President Michael Mulgrew, speaking at a union forum on Wednesday.

Moskowitz, a Democrat who heads New York City’s largest charter network, has not commented publicly on speculation that she is being considered for the top federal education position, and a spokeswoman for Success Academy did not respond to requests for comment.

But Moskowitz met with Trump in New York on Wednesday, Politico reported.

That the charter school mogul would be considered for the job “shows you where they’re headed,” Mulgrew said of Trump’s education agenda.

Moskowitz has been a leading — and often bruising — critic of New York City’s education department. Her network, which has grown to 41 schools and roughly 14,000 students in four boroughs, is meant to prove that publicly funded but privately managed schools can outperform those run by a government bureaucracy — precisely the vision that Trump and his vice president-elect, Mike Pence, have put forth.

Success regularly posts some of the strongest test scores in the city. But the network has also weathered criticism over its discipline practices and accusations that its schools do not serve their fair share of high-needs students. It is under federal investigation after parents filed a complaint alleging that Success discriminated against students with disabilities.

Mulgrew said that criticism makes Moskowitz unfit to lead the nation’s schools.

“Education reform 101: I’m going to take the best and therefore my school is the best, and forget about those who can’t perform,” he said. “That’s not the goal of education in this country, and that’s what Eva Moskowitz is about.”

Also on Donald Trump’s short-list for the next education secretary: Tony Bennett, who ran schools in Florida and Indiana before being voted out of office there; former Washington, D.C. schools chief Michelle Rhee; and an Indiana congressman, Luke Messer.