Warm words between mayor and union chief amid contract negotiations

After that gushing introduction, Mayor Bill de Blasio rode a wave of cheers onstage before launching into a speech to teachers at their union’s spring conference — making him the first mayor to speak at the annual event, he said. De Blasio soon offered some effusive praise of his own, which he made by drawing a contrast to the early years of space travel.

“If the astronauts were our heroes then, who are our heroes today?” he asked the crowd. “Our heroes today are our educators.”

The warm remarks by both leaders reflect their ideological alignment, which stands in stark contrast to the hostility that defined relations between the previous mayor and the union. (Mulgrew called the education policies of former Mayor Michael Bloomberg “disgusting” on Saturday.) The newfound goodwill also points to the fact that each side seeks something from the other: Teachers are hoping for back pay and changes to their evaluation system in a new contract, while de Blasio needs educators to help carry out his signature initiative — the expansion of pre-kindergarten.

After de Blasio’s speech, Mulgrew took to the podium to urge teachers to “take a leap of faith” and work with the mayor and his schools chief, which he said represents an “amazing opportunity.”

Neither man said much about what their collaboration will focus on, beyond the mayor’s marquee proposals — the pre-K drive and new supports for middle-school students — and a couple other issues that both have mentioned before: classroom overcrowding and teacher retention.

In an interview after his talk, Mulgrew insisted that even though he shares many values with the new administration, the two sides are not in agreement on every issue being addressed in the contract negotiations.

“We battle ideas,” he said, though he declined to give any examples.

“Both sides might have a difference of opinion,” he added. “But both sides are motivated by trying to get a better system for the kids.”