YELM, Wash. —  The town council barred residents from mentioning Wal-Mart (search) at meetings, prompting a challenge by civil libertarians who said a "free and accountable" government depends on a citizen's ability to voice concerns openly.

The retailing giant has an application pending to build a superstore, spurring controversy in the small town about 15 miles southeast of Olympia.

In a letter to the council, American Civil Liberties Union lawyer Aaron H. Caplan said his group believes it is unconstitutional to ban any mention of Wal-Mart (WMT) at council meetings. The term "big-box stores" also is banned, as is "moratorium."

The ban began because council members were fed up with complaints about the proposed superstore and related demands for a moratorium on big-box stores, municipal attorney Brent Dille said. He said officials also didn't want to appear biased if the council ever hears appeals in the matter.

"It's the council's meeting. They can decide what they want to hear and what they're tired of hearing," Dille said. "You can understand if you're barraged for two months at meetings — the same people saying the same thing."

The policy has been increasingly restrictive over the past five months. No one who signs up to speak at a council meeting about big-box stores, much less Wal-Mart, is allowed to talk, and anyone who mentions either is told to sit down.

"They just stop you short in your tracks," said Kellie Petersen, who owns a gardening store in town. Petersen is one of several people who have spoken up despite the restrictions.

"My issue was about traffic concerns. I knew enough to use the word 'Wal-Mart' at the very end, so I wouldn't be told to sit down," she said.

The letter from Caplan, who is based in Seattle, said, "The ability of citizens to state their views about matters of public concern is one of the cornerstones of a free and accountable government."

Mayor Adam Rivas said he does not expect the ACLU (search) protest to spark any policy changes and doesn't plan to respond to the letter.

"We don't answer to the ACLU," Rivas said.

The ACLU does not plan to sue over the issue, spokesman Doug Honig said.

A call to national Wal-Mart headquarters seeking comment was referred to local store officials, who didn't immediately return a call.