A Starbucks barista strike is expanding to some 5,000 workers at what organizers said was more than 300 stores in 45 states, just as the company’s busy holiday stretch begins.

Though it still only represents approximately 3% of all U.S. Starbucks locations, it’s an expansion of an action that began last week in three cities.

Organized by the Service Employees International Union and Starbucks Workers United, the strike aims to draw attention to alleged unfair labor practices and stalled…