By Granth Vanaik

Workers at hundreds of Starbucks stores have begun walking off their jobs during a key promotional event on Thursday, demanding improved staffing and schedules, the Workers United said on social media platform X.

The walkout comes on the coffee chain's "Red Cup Day" event, during which Starbucks hands out free red-colored, reusable, holiday-themed cups to customers on their coffee purchases.

The event has typically been a major driver of store traffic, with data from Placer.ai showing a spike in visits on "Red Cup Day" over the years.

The union said on Wednesday that workers at stores in 30 cities across the country had launched "surprise walkouts", ahead of the planned strike on Thursday.

Workers United, which represents more than 9,000 Starbucks employees at about 360 stores across the United States, said on Monday the event was one of the "most infamously hard, understaffed days" for workers, as drink orders pile up and employees end up on the receiving end of abuse from frustrated customers over long wait times.

Starbucks has nearly 10,000 U.S. company-owned locations, and has said that less than 3% of those stores are represented by a union. The company said on Monday the union had not engaged in bargaining talks in more than four months.

Starbucks did not immediately respond to a request for comment on Thursday.

Last year, workers at more than 100 U.S. company-owned Starbucks locations held a one-day strike on Red Cup day, to protest firings, store closures and other actions they said were illegal retaliation by Starbucks against them for unionizing.

Earlier this month, Starbucks said it would raise hourly pay for its U.S. retail workers by at least 3% from 2024, which employees criticized, calling it "tone deaf" given the company's 11% increase in fourth-quarter revenue and the recent wage increases won by the auto workers.

(Reporting by Granth Vanaik in Bengaluru; Editing by Shinjini Ganguli)