Immigrants rights activists have asked a judge to bar Maricopa County officials from charging undocumented migrants of identity theft at allegations they used fake or stolen IDs to get a job.

Lawyers who filed a lawsuit over employment-related identity theft cases by Maricopa Sheriff Joe Arpaio's office and other police agencies argue in court papers filed Thursday that the state laws in question are trumped by federal law.

Arpaio aide Jack MacIntyre said the laws are valid and meant to battle the problem of identity theft.

The lawsuit asks a judge to conclude a state law banning employers from hiring immigrants living in the U.S. illegally is discriminatory.

Supporters of the raids say the law has helped combat identity theft.