The city and the union continued their back and forth over a labor complaint this week, with union president Michael Mulgrew disputing the city’s gripe as misguided.

In the latest swipe as the city and union struggle to reach a deal on teacher evaluations, the city filed a complaint with the state’s labor board Dec. 27 alleging that the UFT was negotiating in “bad faith.” The complaint also accused the union of unfairly trying to tie a deal to perks that were unrelated to the evaluation negotiations, including guaranteed “economic credit” toward a future contract, fewer school closures, and less paperwork for teachers.

Mulgrew’s reply, in a letter to Chancellor Dennis Walcott sent yesterday, asked the city to drop the complaint, which Mulgrew said reflected a ”serious misunderstanding.” Although the union cancelled a negotiation meeting with the city two weeks ago, the UFT still wanted to talk, Mulgrew said.

The letter was the latest in a back-and-forth being closely watched by observers who wonder whether New York’s largest district will come to a teacher evaluation deal. Governor Cuomo has set a deadline of Jan. 17 for districts to strike deals, saying that those that don’t meet the deadline will lose $250 million in state aid.

The disagreement spilled onto the airwaves today, with the both sides trading barbs over who was to blame for the current stalemate.

Mulgrew’s letter yesterday also challenged the city’s claim that the union’s concerns over school closures and paperwork for teachers were entirely unrelated to evaluations. Closing schools would “create a climate of distrust” and would “negatively impact the negotiation process,” Mulgrew wrote. Reducing teachers’ paperwork load, he said, would free up time for teachers to meet with supervisors about their performance.

The letter did not address the city’s concerns about the union’s request for economic credit to count toward future contract negotiations. In an interview today, Michael Mendel, a lead negotiator for the union, said that the request happened months ago.

“The union absolutely denies that the credit had anything to do with negotiations with the new evaluation system,” Mendel said.

In the letter, Mulgrew also wrote that while the union still “desires” an evaluation plan before Jan. 17, it’s “under no legal obligation to negotiate” before a new contract.

Under the state’s evaluation law, the city and the union aren’t required to reach a deal on evaluations until the sides hammer out a new contract. The Jan. 17 deadline, meanwhile, is separate from the evaluation law.

In the letter yesterday, Mulgrew also repeated the concern that drove him to walk away from talks two weeks ago, which is that the city has thought about how it will rollout its evaluation system once it is in place.

Those concerns are rooted in reports from teachers who described practices that were not supposed to happen but could potentially be part of a new evaluation system, such as unannounced observations. Mulgrew also wrote that the union would want a guarantee that teachers would be protected “if the process is improperly implemented.”

Mulgrew Letter