MILWAUKEE (CBS 58) -- A legal group is warning Milwaukee Public Schools (MPS) that a vaccination survey conducted by a high school teacher violates federal law and could result in legal action. 

Students in geometry class at Rufus King were given a survey on the first day of class. It asks if they've been vaccinated and if not, it asks them to explain why. 

The Wisconsin Institute for Law and Liberty (WILL) sent a letter to the MPS superintendent and the principal of Rufus King, telling them that the survey is a violation. 

WILL wants MPS Superintendent Keith Posley to notify every teach that this is unacceptable to avoid further action. 

Read the letter below: