Starbucks has fired seven employees who were leading an effort to unionize a Memphis, Tennessee, store.

The Seattle coffee giant says the employees violated company policy by reopening a store after closing time and inviting non-employees to come inside. The employees used the store to do an interview with a local television station about their unionizing effort.

"These egregious actions and blatant violations cannot be ignored," Starbucks spokesperson Reggie Borges said in an email to CNN. "As a result of our investigation, several partners involved are no longer with Starbucks given the significant violations of these policies."

The employees who were fired say Starbucks was retaliating against them for their unionization efforts.

"They're saying that we had broken policies for allowing customers in the store while it was closed, which was not true," Nabretta Hardin, one of the fired employees, told Yahoo Finance in a phone interview.

The dispute comes as a growing number of Starbucks stores around the country are seeking to unionize.

In recent months, several Starbucks locations in and around Buffalo, New York, have voted to unionize. They're the first of the coffee chain's thousands of U.S. locations to unionize.