CHICAGO — Barrington High School seniors are getting ready to strut across the stage of nearby Willow Creek Community Church to accept diplomas next month.

But the fact that they'll be marching where pastors normally preach on Sundays irks some advocates for the separation of church and state. They say public school graduations don't belong in a house of worship.

"Holding the ceremony at the church sends a message to the students that the school prefers one religion over others and does not accept or include all students equally," said Lonnie Nasatir, Chicago regional director of the Anti-Defamation League.

Though there's no definitive U.S. Supreme Court decision barring public school graduation ceremonies from houses of worship, litigation across the country has made it clear that "absent extraordinary circumstances, graduations should not be held in private church or religious institutions," said the Rev. Barry Lynn, executive director of Americans United for Separation of Church and State.

So far, organizers of several public school commencements have eluded the latest church-state battle erupting across the country. They maintain that churches offer affordable, spacious and weatherproof venues to celebrate the springtime rite of passage.

Deanna Griffin, immediate past president of the Parent Teacher Organization at Barrington High School, said Willow Creek's 7,200-seat auditorium provided convenience and a stately setting when her son graduated last year.

"Did I feel like I was in a church? No," she said. "There's definitely a sense of awe. But I think your brain is transported by the fact that there are people in graduation attire there. It never felt like it was out of place in any way."

Hoffman Estates, Ill., and Barrington high schools have held their graduations at Willow for 14 years. Scott Kasik, the associate principal at Barrington, said the pomp and circumstance at Willow came about for practical reasons.

"It fits the kind of ceremony we have," he said. "It's not like the bleachers at the stadium. There's literally not a bad seat in the house."

Hoffman Estates Principal Terri Busch said holding graduation on school grounds can be more expensive by the time the school pays the price of equipment rental and short-circuit television for the overflow space when it rains. Willow charges about $10,000 to $15,000 to rent the space.

Brian McAuliffe, director of operations at Willow, said the church routinely turns away schools that want to hold their graduations in its auditorium simply because the facility is booked.

"We just don't have the capacity to add on any more (ceremonies)," he said. "It's been a great community outreach for us. You get a lot of people to come here who never would come here otherwise."

McAuliffe said the church doesn't have to cover crosses or other religious symbols because there aren't any in the auditorium where the congregation worships. The absence of iconography makes the space more welcoming for newcomers to Christianity and more conducive for secular events, he said.

"We don't want people to get hung up on that kind of thing," McAuliffe said. "We want people to hear the word (of God). We try to make it an environment where people would be comfortable to sit and listen."

But Lynn, of Americans United for Separation of Church and State, said he's still not comfortable with Willow's hosting graduations if there are other options nearby, such as the Sears Centre Arena in Hoffman Estates, which can seat 3,000 to 11,800.

The Sears Centre has booked 13 graduations — five in one day — this year.

Kelly Winner, whose son Joe will graduate from Hoffman Estates next month, said she appreciates Willow's willingness to offer space over the years. A member of a nearby Reform Jewish temple, she thinks the high school should move graduation to the Sears Centre, which offers comparable pricing and just as much seating. But she doesn't fight it.

"If they did anything religious at graduation, I would be upset," she said, "but it's the content of the ceremony, not the venue, that makes that happen."