A Starbucks in Hollywood on Highland where workers held a vote for a union on Monday, September 30, 2024 in Los Angeles, California.

The workers’ union representing more than 10,000 Starbucks baristas said that union members will go on strike in Los Angeles, Chicago and Seattle on Friday morning.

Workers United, which has a bargaining delegation that represents workers at 525 Starbucks stores in the United States, said walkouts are expected to spread each day and reach hundreds of stores from coast to coast by Christmas Eve unless Starbucks (SBUX) and the union reach a collective bargaining agreement.

The union and Starbucks created a “framework” in February to guide organizing and collective bargaining. Negotiations between the company and Workers United began in April, based on the framework, that could also help resolve numerous pending legal disputes.

“Since the February commitment, the company repeatedly pledged publicly that it intended to reach contracts by the end of the year, but it has yet to present workers with a serious economic proposal,” the union said in a statement late on Thursday.

Starbucks said the union “prematurely” ended a bargaining session this week.

“It is disappointing they didn’t return to the table given the progress we’ve made to date,” the company said in a statement. “We are ready to continue negotiations to reach agreements. We need the union to return to the table.”

The union has been urging Starbucks to increase wages and staffing at its stores as well as implement better schedules.

Starbucks has faced a difficult year: Sales have slipped for three straight quarters, its longest decline in years. Some customers have stopped going to Starbucks because of high prices for drinks and long wait times, and hundreds of its stores have voted to unionize in protest of pay, benefits and working conditions.

In August the struggling coffee chain it had tapped Chipotle CEO and corporate fix-it man Brian Niccol to be its new chairman and CEO, effective September 9.

On just his second day on the job, Niccol said in a letter to employees and customers that he wants to return Starbucks to its roots as a “community coffeehouse” with comfortable seats, design and a clear distinction between “to-go” and “for-here” service.

CNN’s Jordan Valinsky contributed reporting.