On June 24, Bec Goodbourn and Kerry Henderson cast ballots in a union election held for the staff of Book Culture, the independent bookstore where they worked in the Morningside Heights neighborhood of New York. Like the vast majority of the bookstore's workforce, both Henderson and Goodbourn voted in favor of union representation.

By the end of the day, they were both fired.

After letting Goodbourn go in person, her boss, Chris Doeblin, included her on an email in which he explained to the store's management team why she and Henderson had to go.

"It was indicated to me … that two people in our management group voted in the union and effectively undermined the interests of the store. The store always being in opposition to the Union," the email read. "Unfortunately there is no other recourse but to remove these people from our employ effective immediately. Therefor [sic] Bec and Kerry have been fired."

"I was surprised when I saw it in writing," said Goodbourn, 30, a native of Australia who recently moved to the U.S.

Henderson received a personal email from Doeblin.

"I regret to inform you that we cannot continue to employ you," he wrote. "All management has to work together in the best interests of the store and clearly unionization is at odds with that."

The firings of Goodbourn and Henderson led to a strike and protest by Book Culture employees on Wednesday. Among the signs they held up outside the store was one that read, "Rehire The Unlawfully Fired."

The union that won the election, the New York-based Retail, Wholesale and Department Store Union, has filed an unfair labor practice charge with the National Labor Relations Board, the agency that enforces labor law, demanding that the two be re-instated.

Firing an employee for supporting a unionization effort is illegal, as are other retaliatory acts. But Doeblin and the union are at odds over whether Goodbourn and Henderson were actually employees or managers. Under labor law, managers are forbidden from being part of a union, to keep management out of a body meant to represent the rank-and-file workers. Managers, therefore, wouldn't be protected from such a firing.

Doeblin had recently promoted Goodbourn and Henderson to what he says are managerial roles. The two, in turn, claim that their new positions are managerial "in name only."

"We wanted to be considered part of the union; it's a title-versus-practice problem," said Henderson, 22, who just graduated from the New School with a degree in poetry and fiction writing. "I have the title of manager but don't have the same responsibilities as others. I have no power to hire or fire anyone."

If the labor board ultimately determines the two were in fact employees, Doeblin would have run afoul of the law by canning them -- a possibility he readily acknowledges. But Doeblin, who founded the store in 1997 as Labyrinth Books, has gamely defended the firings, even standing alongside protesters outside Book Culture to explain to customers his side of the story.

In an email to HuffPost, Doeblin said that the line between employees and managers in labor law is a "normal, obvious and good thing," and that Goodbourn and Henderson had stepped over it in their support of the union.

"Each of the managers in question accepted a promotion a raise and a new set of responsibilities that necessitates siding with management," he wrote. "[Their] ability to do their job is compromised to an extent that it necessitates firing them. To put it another way, we ask that all of our managers support management and fulfill the directives that they are given."

In a letter to Doeblin, the union's lawyers claimed that two are not really managers and that Doeblin "designated them as such to avoid legal obligations." To "avoid the escalation of this conflict," the union, which represents workers at Macy's, Guitar Center and other retailers, demanded that Doeblin rehire the women and withdraw his challenge to their votes in the union election.

Doeblin has been clear that he feels having a union in the workplace is bad for business, a sentiment that might rankle some of the progressive students and faculty from nearby Columbia University who shop at the store. Much of the store's workers are either recent college grads or working toward their degrees.

"[A]s a business owner it's inherent in the nature of things that a Union is a net problem for a business," Doeblin said in his email. Nonetheless, he added that he plans to deal accordingly with the union, as the overwhelming majority of employees voted in favor of representation: "In practice we have do [sic] and will respectfully deal with our employees' Union and I and our company don't have a problem with that."

According to the union, all but two of the store's employees voted in favor of unionizing.

Like Goodbourn, Henderson said she loves the bookstore. She worked there part-time through much of college and began working full-time after her graduation in May.

"The store is amazing -- there's nothing like it around here," she said.

Her main gripe -- and the reason she supported the union -- was the feeling she could lose her job at any moment.

"We often feel we walk a thin line and any day can be fired," she said.

Goodbourn had only been at Book Culture for a couple of months before she was let go, she said. Without much experience at the store, her support for the union was mostly philosophical. Although union density has declined in both Australia and the U.S. in recent years, organized labor plays a larger role in the economy of her native Australia than it does in America. Nearly 18 percent of Australian workers belonging to a union, compared to just about 11 percent of Americans.

Goodbourn said she believed in collectivism to negotiate working conditions, and she was surprised by management's deep opposition to it.

"Having a union there means you have a third party that can help everyone come together and have a protected space," Goodbourn said. "Your team is a bit more committed if everyone knows their job is secure.