As Republicans seek to hold on to power in the state Senate, an array of labor unions is spending heavily to flip the chamber to Democratic control. On Monday, Majority Leader John Flanagan in a radio interview called them the "forces of evil."

“We have incumbents who are in tough races and we have outside forces, and some of them have become almost like the forces of evil, spending millions and millions of dollars,” said Flanagan.

And he specifically named the New York State United Teachers union as chief among those outside groups aiding Democrats.

“Well, I believe that NYSUT has demonstrated they want one-party rule. They don't like the way things are going. They spent over $5 million the last cycle,” sad Flanagan.

The statewide teachers union is spending hundreds of thousands of dollars in key Senate races against Republican candidates — but Flanagan's comment took the union by surprise.

“Who is he talking about? Is he talking about a kindergarten teacher? Is he talking about a bus driver? Who is this evil person?” said Andy Pallotta, NYSUT president.

Senate Republicans and the teachers union in the past have been allies. But this year the relationship soured after Republicans did not hold a vote on a bill that would end the linkage between state exam results and how teachers are evaluated.

“But Senator Flanagan would not let that come to a vote. I believe that's a lot of distance making from what he did at the end of session," said Pallotta.

Labor unions have mobilized ahead of the general election next month as part of a broader get-out-the-vote effort for competitive House and state legislative campaigns.

“Labor is definitely fired up and NYSUT members are definitely fired up calling them a force for evil,” said Pallotta.

Republicans on Monday accused labor unions of illegally coordinating their super PAC spending; a NYSUT spokesman has called the allegations baseless.