Starbucks' union says workers are walking off the job at some 300 — out of over 10,000 — stores across the U.S. as contract negotiations falter. The company urges it to return to the bargaining table.

Starbucks baristas went on strike at several stores in Chicago, Seattle and Los Angeles on Friday, with their union warning the walkouts could spread to hundreds of cafes by Christmas Eve if the coffee giant does not meet workers’ demands at the bargaining table.