Chicago Public Schools chief Barbara Byrd-Bennett has threatened to discipline any teacher that refuses to administer an annual state achievement test next week, according to a letter obtained by the Chicago Sun-Times.

The letter, sent out Thursday to principals, claims teachers could face the harshest repercussion from boycotting the test — losing their state education certification.

Teachers should also be ordered to leave the school building if they refuse to administer the test, according to the letter.

“The Chicago Board of Education will discipline any employee who encourages a student not to take the ISAT or who advocates against the ISAT on work time for insubordination and for any disruption of the educational process,” Byrd-Bennett said in the letter.

The order from the CPS boss comes as teachers at a Little Village school have unanimously decided to boycott the Illinois Standards Achievement Test.

“This is really absurd and harmful,” said Chicago Teachers Union Vice President Jesse Sharkey.

He said the threat to state certification, which is at the heart of a teachers’ ability to work, is not being taken lightly.

“We’re not taking that as an idle threat,” Sharkey said. “Our lawyers are currently working on that.”

And the command that teachers be sent home if they refuse to administer the test has Sharkey wondering what CPS officials are thinking.

“That’s the kind of direction that would be reserved for very serious infractions,” he said.

The teachers who don’t want to administer the test just want to teach, and their students just want to learn, Sharkey said.

Earlier this week, about 40 teachers at Maria Saucedo Elementary Scholastic Academy agreed they would all refuse to administer the test.

The ISAT is scheduled to be administered beginning March 3, but parents can choose to opt their children out of the test.

Sarah Chambers, a special education teacher at Saucedo, said Thursday morning that about 500 students have submitted letters to opt out of the test — that’s about 65 percent of all students that would be required to take the test at that school.

Students in grades three through eight take the test.

Teachers at Saucedo said the test takes away from crucial instructional time, especially because the test isn’t used for a specific district purpose any longer.

Last month, Byrd-Bennett wrote a letter to parents that explained that a new standardized test would replace the ISAT and would be used for school promotion in grades three, six and eight. The other test, the NWEA MAP, will replace the ISAT for enrollment in selective enrollment schools, Byrd-Bennett said. In that letter she encouraged parents not to opt out of any test.

The ISAT is required by federal law under No Child Left Behind, and it is used to measure, among other things, adequate yearly progress. CPS has not met that benchmark in recent years. The test is also required by state law, CPS said.

In Thursday’s letter to principals, Byrd-Bennett said the test is not meaningless.

She said the test, which is aligned to Common Core Standards, provides educators “an important first look at how well their students are doing on these more rigorous expectations.”

Byrd-Bennett also told principals that schools with low participation rates on the ISAT may lose federal funding, among other concerns.

And the testing will go on, she said.

If a teacher refuses to give the test, a principal should find another employee to administer it, Byrd-Bennett said.

Email: bschlikerman@suntimes.com

Twitter: @schlikerman