John Mackey, the chairman and chief executive, founded the company on the principles of open communication and empowered employees. Whole Foods workers here have found, however, that the principles do not include embracing labor unions.

The first — and so far only — successful union drive in Whole Foods' history took place last year in this liberal, pro-labor state capital. In the aftermath of the drive, there were allegations of dirty tactics by each side; a personal plea from Mr. Mackey for the Madison employees to "expand into love"; and the firing of two pro-union employees over what they say was, almost literally, spilt milk.

Many supermarket workers count on unions for gains in salary, working hours and conditions. Sometimes these concessions drive prices up, and union campaigns often create bad feelings between labor and management. But the tension is especially striking at Whole Foods, which prides itself on social consciousness. Labor advocates now speak of Whole Foods in the same breath as Wal-Mart Stores, which has fiercely kept itself nonunion.

In a written statement, Michael Duffield, a company spokesman, said that Whole Foods fosters "a decentralized, nonbureaucratic environment, and this ability to be fast and flexible is a large part of our success."

"Work environments dominated by unionization are not often characterized in this way," Mr. Duffield added, "and that is why John Mackey, and Whole Foods Market, does not believe that representation by a union is in the best interests of team members" — the company's term for employees. Mr. Mackey declined to comment.

According to Jennifer Chatman, a professor of management at the University of California at Berkeley: "The chain prides itself as a unionless utopia where employees are team members empowered to solve problems. Because it's a progressive company, it views unions as a sign the company isn't providing employees with all that they need. If you look beyond the immediate financial implications, there's a real identity issue here."

But the financial implications could affect Whole Foods' long-term profits. The company's "unique, labor-intensive culture is indicative of its emphasis on customer service," said Neil Stern, a senior partner for McMillan/Doolittle L.L.P., a retail strategy company. "With unionization comes higher labor costs, and Whole Foods could either absorb those added costs or pass them on to their customers."

Whole Foods opened its Madison store in 1996, and workers soon found themselves at odds with management over a host of issues, like rising health insurance costs. The rumblings grew louder last spring, when the company told store employees they would have to adhere to a dress and appearance code. In this casual-dress city, that meant losing the brightly colored hair, political buttons, and, for Debbie Rasmussen, a "juice bartender," the piercing from her upper lip. "It struck a nerve with a lot of people," Ms. Rasmussen said.

Mr. Duffield said the company does not require uniforms, and the Madison dress code had been more liberal than at other stores. Despite union claims to the contrary, he said, bringing the code into line with other Whole Foods stores did not change its commitment to celebrating individuality.

Whole Foods acknowledged a larger breakdown in communication, blaming store managers for getting away from the company's culture. The store changed the top managers at the Madison store in May, but the move did not satisfy many workers who believed the problems came from higher up.

Salary issues also fueled the push for a vote. Both Whole Foods and union officials agreed that the store paid competitive wages. Mr. Duffield added that the company has more employees per store than many grocers and a substantially larger ratio of full-time to part-time workers.

Unlike union stores, however, where raises are given by seniority, pay increases are disbursed more subjectively. At the Madison store, workers with the same seniority found they were earning different amounts, and in some cases, new employees made more than existing ones, said Brendan O'Sullivan, a deli department worker who helped organize the campaign to join United Food and Commercial Workers Local 1444.

Soaring health insurance costs were also taking a bite out of paychecks. Many unionized grocery stores fully cover employee insurance, but Whole Foods does not, said Jim Hepner, organizing director of Local 400 in Landover, Md.

When Madison employees voted 65 to 54 in July to organize, Whole Foods executives appeared crestfallen.

In a memo to employees several days later, Mr. Mackey called the vote "a very sad chapter in the history of Whole Foods Market."

"Madison made a mistake in their choice. It may take time for them to realize it, but I believe that they eventually will. We all make many mistakes in life. It is all part of our growth process because that is how we learn, that is how we grow," Mr. Mackey wrote. "When confronted by great stress in life, we have but only 2 choices: 1. Contract into fear. 2. Expand into love."

The workers contend that since the July election, management has fought them and dragged its feet at every turn. A few days after the election, Whole Foods appealed the vote to the National Labor Relations Board, asserting that several workers sought employment at the store to influence the election, and that a different union unlawfully courted a Whole Foods employee by offering him a job elsewhere in exchange for his vote for the union. The union asserted that it did not offer the employee any job until after the votes were counted. The board rejected those claims, ruling the election valid, and collective bargaining began.

But Whole Foods' lawyers canceled two bargaining sessions, citing time conflicts. Local 1444's president, Dan Welch, said Whole Foods was trying to stall until a year after the election, when it would be legal for pro-management workers to petition to decertify the union. The company says it is bargaining in good faith.

"It's just kind of goofy, to be real frank with you," said Chris Sauter, the Local 400 organizing director in Maryland. "It's, `Look, we want you to be a part of it, we want you to have some part to play in the decision-making process, take ownership of the store.' Yet when it comes to really getting a say and participating in collective bargaining, they fight it tooth and nail."

In November, two employees who were leaders in the unionization drive were fired over an incident that they say they thought was innocent enough. Ms. Rasmussen said she accidentally made a drink with soy milk rather than skim milk. Instead of pouring it down the drain, she gave it to a co-worker, Julie Thayer, to drink, they said.

Both were sent home, and they were fired the next day. They appealed to the National Labor Relations Board, which dismissed their claim. The union has appealed.

"They don't recognize the hypocrisy that this company has made billions on social and environmental consciousness," Ms. Rasmussen said. "It's so hollow."

Mr. Duffield said the two were fired for cause and the dismissals were unrelated to their views on unionization. Whole Foods employees, he said, are a largely happy bunch who appreciate perks like profit-sharing and 5 percent days, when that portion of after-tax income is donated to community organizations.

"A large part of the appeal of Whole Foods Market to our millions of customers and our team members, they tell us, is based on the fact that we are making the world a better place, and have been for over 22 years," Mr. Duffield said.

Things, meanwhile, have gotten ugly in Falls Church, Va., where a second Whole Foods store was set to vote last month on unionizing. After charges of union and management misdeeds flew back and forth, the National Labor Relations Board halted the election.

The labor board is investigating numerous union charges, including one that Whole Foods coerced and retaliated against pro-union employees. Whole Foods packed the store with workers from other locations to influence the vote, the union contends. Mr. Duffield would not comment. In an April 11 letter to employees, Mr. Mackey asserted that some workers did not know they were formally supporting the union when they signed their union cards.

Unions have also recently picketed the Chelsea store in Manhattan and stores in northern New Jersey, and union advocates are starting an organizing drive in Austin, Whole Foods' hometown.

Unions around the country have added Whole Foods to their boycott lists, which also include Wal-Mart.

Jeff Metzger, publisher of Food World magazine in Columbia, Md., said successful companies tend to become targets of organizers. "They've moved the needle forward in the last few years," he said of Whole Foods. "Success breeds interest."