Mayor Richard Daley says Chicago Public Schools teachers who may have doctored grades represent a “failure of their profession.”

Daley was responding to a published survey that found many teachers have felt pressure from colleagues or parents to change a student’s grades.

The survey by the Chicago Sun-Times and the Chicago Teachers Union found 35 percent of CPS teachers have felt pressure from a coworker to change grades for the better.

And it found 21 percent of them actually did.

Mayor Daley says that is “unacceptable.”

DALEY: Why are you cheating that student and their family? Why are you doing that to them? I flunked courses. I admit it. And I had to go to a summer school. Or I had to get a tutor. What’s wrong with that?

Daley urged the school district to get to the bottom of the matter.

Chicago Public Schools Inspector General James Sullivan says his office is investigating the allegations.