Schools Chancellor Dennis Walcott said he wants to reach an agreement with the United Federation of Teachers on teacher evaluations in the next two weeks, by Dec. 21, and has asked his team at the Department of Education to clear their calendars to do so.

“After everything our schools, staff, students and families have been through this fall, they deserve a restful holiday break, free of worry about potential cuts to schools,” he said.

Walcott also said the urgency stems from a deadline set by Governor Andrew Cuomo who is urging all the school districts across New York to have their evaluation plans approved by the state by Jan. 17. If they don’t, they risk losing an almost 4 percent increase in state education aid. In New York City, the funds amount to about $250 million and have already been allocated for the current school year.

Speaking at an event Wednesday sponsored by the Manhattan Institute, Walcott used the potential loss of funds to paint a bleak picture. Without an agreement, he said, the city would be forced to make deep cuts.

“We would expect that cuts would lead to fewer teachers being hired, which will probably lead to larger class sizes,” said Walcott, according to prepared written remarks. He added that schools could see a reduction in guidance counselors, social workers and other school support staff.

Michael Mulgrew, the teachers’ union president, responded quickly to the chancellor’s remarks, calling on Walcott and Mayor Michael Bloomberg to “stop playing politics” with the city schools.

“Rather than establishing bogus deadlines and threatening parents with the loss of teachers and services, they should be focusing on reaching an agreement that will actually help make the schools better,” said Mulgrew in a written statement.

Walcott said he wanted a deal on evaluating teachers that “recognizes how difficult teaching is today.”

“The new evaluation system also needs to capture a new ethos; one that treats teachers like professionals and holds them accountable for progress — while providing appropriate supports so that educators can become the most effective they can be,” he said. “We need a new system that accurately aligns teacher practice with student outcomes.”

Walcott’s comments come on the same day that the Campaign for Fiscal Equity, now a project of the New Jersey-based Education Law Center, rallied at City Hall to call for increased funding to schools. David Sciarra, executive director of the Center, said putting a contingency on any much-needed increase in education funding “should be completely off the table.”

“At the same time that the state has walked away from its obligation to fairly fund the poorest schools in our state,” said Sciarra, “to then turn around and use the threat of withholding funding for those very same programs that kids need, frankly, is unconscionable.”

The Campaign for Fiscal Equity sued New York state in 1993, saying lawmakers inadequately financed poor school districts. The group won its lawsuit more than a decade later and subsequent legislation in 2007 promised to put more than $5 billion in New York City schools alone, phased in over several years.

However, even with the state setting aside funds borne out of the lawsuit, it cut overall education aid to districts two years in a row due to the poor economy. The increase in state aid this school year, tied to teacher evaluations, brings education funding statewide to $20.3 billion. But that amount is still about $1 billion less than total state aid for the 2008-2009 school year, according to the Citizens Budget Commission.

“Five years ago, I noticed immediately that schools north of 125th Street were different,” said Miriam Aristy-Farer, who has a son in elementary school and spoke at the rally organized by the Campaign for Fiscal Equity. She said many schools in Manhattan’s District 6 lacked physical education programs, after-school programs, art classes and overall support services for children.

“Does one guidance counselor per every 500 children make sense in a community where for many children school is their only safe haven?” she said.

The group gathered at City Hall planned to march in Albany Wednesday afternoon to demand that the state fulfill its obligation to fund poor school districts. The Campaign for Fiscal Equity said it would be prepared to file another lawsuit if the governor’s next budget does not reflect a significant increase in education funding.