The Maryland Court of Appeals, the highest appellate court in the state, has agreed to decide whether Montgomery County’s police union can challenge a law that curtails expansive police bargaining rights, a lawyer for the union said Tuesday.

In November, county elections officials certified a petition putting the law to referendum. Passed unanimously by the County Council last summer, the law prevents the union, Fraternal Order of Police Lodge 35, from negotiating with county officials on day-to-day duties, such as checking e-mail.

The county quickly sued to block the petition. Last month, a county judge, Eric M. Johnson, struck down the petition, saying there were problems with the information provided by the petitioners who collected the signatures.

The police union appealed the ruling, and F.J. Collins, the union lawyer, said the Court of Appeals has scheduled a hearing Aug. 16 to hear the union’s case. If the Court of Appeals reverses Johnson’s ruling, the law would appear on the ballot this November.