CHICAGO (CBS) — Chicago Public Schools officials have sent layoff notices to 550 teachers and 600 clerical support staff, but said the teachers will be able to apply for other open jobs with the district for next school year.

For the fourth time in five years, the district said the teacher layoffs were the result of enrollment declines at some schools, though CPS has not identified which ones.

The Chicago Teachers Union quickly blasted Mayor Rahm Emanuel and CPS.

Their message?

“Fund your schools,” said union vice president Jesse Sharkey. “If you keep laying off the teachers and staff you are going to destroy on of the most critical resources that we have in the society.

Union president Karen Lewis ridiculed the city’s focus on landing the new George Lucas museum and President Obama’s library

“Do we want ‘Star Wars’ museums or public neighborhood schools? Do we want presidential libraries or librarians for every child?” Lewis said.

However, the district said it expects to have approximately 1,780 vacant teaching slots for next school year, and teachers who received layoff notices can apply for those positions. Approximately 1,400 of the open slots are for full-time teaching positions.

“On average, more than 60 percent of displaced teachers have historically found positions elsewhere in the District. CPS expects this year to meet or exceed our historical experience,” CPS officials said in a handout.

The teachers and clerical staff all are represented by the Chicago Teachers Union.

Lewis called the cuts – nearly 5,000 over the past year — “yet another brutal attack on public education in Chicago.”

“This loss of teachers and staff will directly impact the quality of instruction offered in our schools, and is unnecessary and shameful for a district that claims to provide a high-quality education for its students,” Lewis said in a statement.