The workers union at Starbucks is claiming the coffee chain is shutting down a recently unionized cafe in retaliation for its activist efforts, Bloomberg News reported.

It’s the latest escalation between a rapidly growing national labor movement and the coffee giant.

Workers United, the union that’s backing organizing efforts at Starbucks, reportedly said in a Friday filing with the National Labor Relations Board that Starbucks is violating federal labor law by permanently closing an Ithaca, New York, store. The group alleged it was in retaliation since employees at the location voted to unionize in April, according to the organization’s Twitter account.

Starbucks said that it opens and closes stores “as a regular part” of its operations. “Our goal is to ensure that every partner is supported in their individual situation, and we have immediate opportunities available in the market,” a Starbucks spokesperson said in an email to CNBC.

The union is asking the agency to seek a federal court injunction to quickly prevent or reverse the store closure, according to the report.

Around 100 Starbucks cafes have voted to unionize under Workers United, while only 14 locations have voted against unionizing. Workers United announced this week it was creating a $1 million fund to cover lost pay for baristas who go on strike.

Workers United has filed at least 175 complaints against the coffee chain for unfair labor practices, CNBC previously reported. Starbucks has denied wrongdoing.

Read the full report from Bloomberg News here.

— CNBC’s Amelia Lucas contributed to this report.