In rejecting a bill that would have carved out changes to the state’s teacher evaluation law, Gov. Andrew Cuomo “reneged on an agreement” the New York State United Teachers union charged in a statement.

Cuomo on Monday night vetoed a measure that would provided a “safety net” to teachers in the evaluation system would have altered the impact of the Common Core standards.

The governor negotiated the bill directly and introduced it himself as a “program bill” with a gubernatorial waiving of the three-day aging process.

But Cuomo had grown increasingly uneasy with the bill, and in recent weeks indicated he wanted to push a wholesale overhaul of the state’s education system.

In its statement, NYSUT knocks Cuomo for the support he’s received from wealthy proponents of charter schools, which the governor has championed in Albany.

“With this veto, the governor has decided that teachers are the only ones who should be held accountable for the state’s failed implementation of the Common Core,” the teachers union said in a statement. “We can’t understand why he is refusing to sign his own bill. What has changed? Could it be that the governor is doing the bidding of billionaire hedge fund managers — many of whom, like Paul Tudor Jones, don’t even live in New York state? This governor has to decide whether he’s going to support the goals of students, parents and teachers or those of billionaires who want to destroy public education in order to privatize it and profit from it.”

Cuomo is expected to lay out a new education policy direction in his State of the State address next month.

The union is expected to protest the veto outside of the Executive Mansion on Wednesday, when Cuomo is due to hold a traditional New Year’s Eve meet-and-greet of the public.