An arbitrator late Friday struck down the city's controversial move to make teachers at 24 struggling schools reapply for their jobs, saying Mayor Michael Bloomberg's plan violated union contracts.

The city planned to shut down the schools and open new ones in their place, forcing more than 3,500 teachers, administrators and school aides to reapply for their jobs.

The state education commissioner signed off on the plan.

The United Federation of Teachers said the arbitrator's decision means the staff in the affected schools will be able to keep their jobs for the next school year.

UFT president Michael Mulgrew spoke to NY1 about the decision on "The Call."

"It sends a very clear message that to try to do a backdoor scam closing of schools in order to punish school communities is not going to be accepted," he said. "The arbitrator clearly ruled that the mayor's plan was wrong."

Mayor Bloomberg and Schools Chancellor Dennis Walcott said they will appeal the decision.

In a joint statement, they said, "The ruling puts the career interests of adults ahead of the educational needs of children, and it contradicts the State Department of Education’s decision authorizing our plan."

The UFT says parents, students and teachers need the Department of Education to come up with strategies to fix struggling schools rather than give up on them.

"The city should focus in on sitting down and talking to the union to make sure that everyone is working together in order to give the best education for our children," said City Councilman Robert Jackson.

Education officials said that the ruling puts in jeopardy nearly $60 million in federal aid for struggling schools.