According to BBC, a union representing over 11,000 Starbucks baristas in the US has announced a five-day strike starting on Friday due to disputes over pay and working conditions.

The walkouts will begin in Los Angeles, Chicago, and Seattle, with plans to expand to hundreds of stores by Christmas Eve if an agreement is not reached. Starbucks has defended its average pay of over $18 an hour and “best-in-class benefits,” but Workers United highlights a pay disparity between baristas and senior executives.

“Taken together they are worth an average of $30 per hour for baristas who work at least 20 hours per week,” it said.

The strike coincides with a protest by the Teamsters union against Amazon, with delivery drivers at seven facilities walking off the job over labor contract negotiations.