Unionized Starbucks workers walked off the job Thursday to press their demands for contract negotiations and highlight their complaints about staffing and scheduling issues.

The union representing the striking workers, Starbucks Workers United, said thousands of workers at more than 200 stores participated in the strike. Starbucks said workers were protesting at fewer than 100 stores, and most of those stores remained open. The company has approximately 9,300 corporate-owned stores in the United States.

The walkout coincides with an annual Starbucks promotion, Red Cup Day, in which customers receive bright red reusable cups if they order a holiday-themed drink, such as a Sugar Cookie Almondmilk Latte.

Starbucks Workers United has said events like Red Cup Day force employees to handle more orders than usual but without enough staff.

Union workers say the company has refused to negotiate over personnel and scheduling issues that are particularly acute those days, and the union filed an unfair labor practices complaint with the National Labor Relations Board on the issue this year.

The union represents more than 9,000 Starbucks workers at more than 300 stores nationwide. Employees at some unionized stores began the strike on Wednesday with the aim of surprising the company, which was aware of Thursday’s action.

Starbucks says the union is the side that has impeded bargaining sessions by insisting on holding the meetings online, with rank-and-file members watching, rather than bargaining teams sitting in person.

“We hope Workers United’s priorities will change to include the shared success of our partners and negotiating contracts for those they represent,” company spokesman Andrew Trull said in a statement.

The union is calling on the company to suspend mobile ordering on promotional days, which it says have become more frequent.

Daisy Federspiel-Baier, a shift supervisor at a Starbucks in Seattle, said her store received more than 200 orders in half an hour during an October promotion in which customers could get 50 percent off any drink. The store was so crowded that some drinks and food went to waste and orders were suspended, Federspiel-Baier said.

“I saw how baristas were on the verge of a state of mental breakdown, being verbally berated by customers and feeling pressure from bosses to continue working when it was unreasonable to do so,” he said.

In a statement, Starbucks acknowledged that promotions “may change store traffic and patterns,” but added: “Our stores often receive additional work hours to increase staffing in support of planned promotional days.”

Rachel Simandl, a shift supervisor at a unionized Starbucks in Chicago, where employees struck Wednesday and Thursday, said staffing problems were more chronic, leaving workers exhausted and hurting business by increasing wait times. for customers and reduce the quality of service.

“Honestly, what we need is to have more coverage on the court,” Ms. Simandl said. “Instead of just three people, have four or five people. It makes a big difference in the way the day flows.”

The strike is the latest development in a battle between the company and the unions. After two initial election victories in the Buffalo area in December 2021, the union drive quickly spread. About 70 stores ran in union elections in March 2022, but momentum dissipated. Nearly 20 stores ran in union elections last month.

Of the stores whose election results have been certified by the National Labor Relations Board, 363 voted in favor of unionizing, while 71 voted against unionizing.

In September, a labor board judge ruled that Starbucks had violated federal law by limiting benefit increases and improvements to non-union workers. Another administrative judge ruled in March that Starbucks had repeatedly violated federal labor laws by illegally disrupting union organizing and firing employees who tried to unionize.

In June, unionized workers declared a weeklong strike at more than 150 stores, protesting what they said was the company’s ban on Pride Month clothing and the treatment of LGBTQ workers, a claim that management he denied. Starbucks said the protest had temporarily closed 21 stores.

Starbucks Workers United said Thursday’s Red Cup Day protests had spread to about a dozen non-union stores.

One was near Flatwoods, West Virginia, where Justin Copenhaver, a shift supervisor, filed a petition to unionize with his coworkers this year. The effort was rejected in March, but the union accused the company of tampering with the election.

On Thursday, Copenhaver picketed outside the store with three other employees.

“I want to show the company that we are the ones who provide the money and that we can prevent money from coming in,” he said.

Noam Scheiber contributed with reports.