A small church in a Phoenix suburb says its local government puts far stricter limits on its roadside signs advertising Sunday services than it places on politicians, real estate agents and other groups, and is asking the Supreme Court for relief.

The justices are hearing arguments Monday in a case from Gilbert, Arizona, that raises First Amendment questions about how governments may regulate their citizens' speech. The Good News Community Church and Pastor Clyde Reed sued Gilbert, claiming that religious groups are treated more severely than others.

Gilbert allows so-called directional signs, like the ones put up by the church inviting people to Sunday worship, to be no larger than 6 square feet. They must be placed in public areas no more than 12 hours before an event and removed within an hour of its end. Signs for political candidates, by contrast, can be up to 32 square feet and can remain in place for several months.

Lower federal courts upheld the town's sign ordinance because the distinction it draws between different kinds of temporary signs is not based on what a sign says.

The church is joined by religious groups and the Obama administration in urging the Supreme Court to strike down the ordinance.

The church, which serves roughly 30 adults and up to 10 children, argues that the regulation's significant difference in the size of the signs and how long they can be displayed is essentially regulation based on content, which the Supreme Court only rarely allows in First Amendment cases.

"Simply put, to prevail in this case, Gilbert must explain why a 32-square-foot sign displayed in the right of way virtually all year long is not a threat to safety and aesthetics if it bears a political message, but it is such a threat if it invites people to Good News' church services," the church said in court papers.

The National League of Cities and other associations of local officials are backing the town and warning that a ruling in favor of the church would make it "nearly impossible" for cities and towns to craft sign regulations that deal with a community's appearance and safety.

A decision is expected by June in Reed v. Town of Gilbert, 13-502.