CHICAGO – A federal judge on Wednesday issued a preliminary injunction blocking a suburban Chicago school district from enforcing a new state law requiring a moment of silence, calling the statute “likely unconstitutional” and vague.

Judge Robert W. Gettleman asked the parties in the case to return to federal court on Thursday when he said he would consider making the injunction statewide.

Gettleman issued the injunction after atheist activist and talk-radio host Rob Sherman filed a lawsuit against Township High School District 214.

Sherman, whose daughter is a freshman at Buffalo Grove High School, claims the new state law violates the U.S. Constitution and is an attempt to inject religion into public schools.

His attorney, Gregory Kulis, asked the judge to extend the injunction to the rest of the state, and Gettleman said he wanted to think about the decision overnight.

“Things are moving in a positive direction,” Sherman told the Chicago Tribune after the judge’s ruling.

The Silent Reflection and Student Prayer Act already let schools in Illinois have a moment of silence if they desired to do so. The new law, which went into effect last month, changed the word “may” in the law to “shall,” mandating a moment of silence.