The president of the Philadelphia Federation of Teachers warned this week that mounting tensions between the union and the city school district could adversely affect ongoing contract talks.

Jerry Jordan said that his union would file a grievance over the latest contention, which centers on layoff notices sent last week to 25 union employees.

The largest number of those being let go this month are 15 non-teaching assistants, or NTAs.

This follows several recent statements by Superintendent Arlene Ackerman about wanting to hold teachers more accountable, which has left a growing number of teachers feeling disrespected, Jordan said.

"Creating a climate of trust and mutual respect is critical to moving the district forward," he said.

The layoffs don't help, said Jordan, who plans to update his 16,000 members during a June 22 meeting.

The union's contract expires Aug. 31.

Prior to the start of contract negotiations, Ackerman said that she would like the new contract to contain a performance-pay provision and more flexibility to move veteran teachers to struggling schools.

Few other details have emerged, as the talks are taking place in near-secrecy.

"I have to take direction from the membership . . . If the membership does not feel valued and respected, it becomes difficult for people to think about doing things differently," Jordan said.

Charged with helping to maintain order in hallways, cafeterias and throughout buildings, NTAs have long been fixtures in city schools.

Terminating 15 will make it that much more difficult to keep staff and students safe in the affected schools, Jordan said.

He noted that Germantown High School lost all of its NTAs in 2007, the same year math teacher Frank Burd suffered a broken neck after two students jumped him in retaliation for confiscating one of their iPods.

"NTAs are an important part of setting the right climate and tone in a building," Jordan said.

"They are on the perimeter of school grounds; they make sure movement in hallways is orderly; they move students along to class and make sure they are not loitering in bathrooms."

Jack Stollsteimer, appointed in 2006 by Gov. Rendell as the district's safe-schools advocate, said that he had not heard about the job cuts, but said yesterday that NTAs are necessary.

"As a general principle, well-trained NTAs are a crucial piece of school safety. They play a vital role," he said.

Still, a growing number of schools have none, as their ranks diminished under Ackerman and the previous schools chief, Paul Vallas. Currently, 178 are still in schools, district spokeswoman Cecilia Cummings said yesterday.

Vallas maintained that principals should hire part-time community-based groups rather than unionized NTAs to provide additional security.

Critics charged that it was a dangerous way to save money.

Cummings said that the layoff decisions had been made by principals, not Ackerman.

"These are decisions that have been made at the principal level as they set their staffing plans for next year in line with their strategic objectives," Cummings said.

"The number of NTAs have declined over the years as principals determine the best way to achieve both their academic and safety objectives," she continued.

"And given that serious incidents have declined by 14 percent, it appears that the principals are making the right decisions."

Of the 15 schools that are losing NTAs, seven are on the state's 2008-09 persistently dangerous schools list: Edison, Frankford, Lincoln, Fels, South Philadelphia and Strawberry Mansion high schools, and Stetson Middle School.

Other schools that are losing NTAs are Mastbaum and Dobbins high schools, and Feltonville Arts, Meehan, Marin, Fitler, Conwell and Blankenburg schools.

Also being laid off are six community-relations liaisons and four others in nonteaching jobs. *