Chris Walsh is hopping mad. Literally. Walsh, 24, hurdles over a table stacked with posters to retrieve his Panasonic video camera from a back office, so he can play me the damning evidence.

"They screwed us!" says Walsh, the blond-haired, ear-pierced owner of University Avenue's the Wall poster shop, who bears a resemblance to Eminem. He cues up footage of the University District Street Fair on the Ave (May 17 and 18). The camera's tiny screen shows a stretch of street-fair vendor booths lined up in front of the Ave's regular storefronts. Walsh's voice provides on-camera commentary: "They're backed up right to the curb! There are no customers on the sidewalks." Walsh says his shop--a neatly organized store with thousands of posters hung on the dark walls and piled on tables, from black-and-white kitten photos to fine art by Salvador Dali--lost about 75 percent of sales during this year's fair, compared to last year.

In the past, street fair booths were in the middle of the Ave--facing businesses. Customers walked on either side of the street, checking out both fair vendors and regular businesses. But a recent Ave renovation narrowed the street, and the Greater University Chamber of Commerce--the fair's organizer--had to rearrange the booths to meet fire code.

The configuration irked Walsh, who--with few customers at his store during the fair--spent the weekend collecting business owners' signatures on a petition denouncing the layout. He got nearly 100 names. Now, armed with the support of a sizable chunk of Ave businesses, Walsh is taking it a step further: He's on a mission to overthrow the Chamber's leadership and give Ave businesses a bigger voice. "They're going to have to get rid of [Chamber Executive Director] Teresa [Lord Hugel], or we're starting a merchants association," Walsh says, leaning on his shop's counter. "We're not being represented."

Walsh's mutiny may seem like an overreaction to something as simple as a botched weekend festival, but it was the final straw for Walsh and other business owners. They've been fuming for nearly a year over the massive renovation, as block after block of the Ave is redone. "No one was more excited than me for the street fair," says Gayle Nowicki, owner of Gargoyles Statuary, a gothic-inspired shop just past N. 45th Street. But this time, her business was down by half. Many other businesses report similar losses--50 to 75 percent less than past street-fairs. One bar that usually makes 10 grand only made $3,000, Walsh says.

Walsh thinks the Chamber, a group of landlords, proprietors, and property owners that promotes the neighborhood's commercial interests, isn't helping small businesses. And furthermore, Walsh says, the Business Improvement Association (BIA)--a group started by the city and administered by the Chamber to fund street cleaning and security--isn't getting his due until things change. He owes $220, and plans to withhold it until the city notices the Ave's hurting businesses; Walsh wants other owners to join the dues strike.

Walsh called a May 29 breakfast meeting at Costas Greek restaurant to talk about the Chamber, the BIA, and the street fair. Letters went out to the Ave's businesses: "The current groups that purport to represent our business community no longer represent the businesses in our area," the blunt letter reads. "Preferring instead to represent the interests of the property owners who, for the most part, are absentee landlords." On the agenda: discussions about forming a new merchants group to represent businesses, dissolving the BIA, and even ousting the Chamber.

So far, there's support on the Ave for a business owners' group. But it seems most owners are reluctant to fall in line with Walsh's full revolution--many back Chamber Executive Director Hugel, who spent the week explaining the fire code issues to businesses. "I 100-percent support Teresa," says Charles Grimes, owner of M. J. Feet shoe store and president of the BIA's board. "She's the best director we've had in a long time." He didn't sign the petition.

At the Chamber, Hugel is well aware of the Ave tension. "I think the people who are complaining do not understand the bigger picture," she says, pointing out that the fair is part of the Chamber's mission to promote the entire district. "The Chamber's been around for 87 years. It's not going away because they're pissed." That said, she's not opposed to a merchant's association.

Walsh has clearly tapped a nerve on the Ave. From coffee shop owners to music store managers, folks are planning to attend the May 29 meeting. Whether they rise up against the Chamber and the BIA remains to be seen.

amy@thestranger.com