Starbucks Baristas in some locations plan to strike until Christmas Eve, starting with cafes in Los Angeles, Chicago and Seattle on Friday.

The strikes will escalate every day and reach new markets as Starbucks Workers United pushes for better pay for baristas. Starbucks is “backtracking on our promised path forward,” the union said in a post on X announcing the strikes.

The stop could lead to longer waits for holiday drinks and popular Starbucks goods in the days leading up to Christmas, when many Americans stay home from work and school or buy last-minute gifts.

Relations between the company and the union have become frosty again after a thaw earlier this year. In late February, the two sides jointly agreed on a “basic framework” that would include a process for reaching collective bargaining agreements on individual deals. According to Starbucks, they have since held more than nine rounds of negotiations in 20 days.

Earlier this week, Starbucks and the union met for the last scheduled collective bargaining hearing of the year. But ahead of the meeting, Starbucks Workers United baristas voted to authorize a strike if the coffee giant didn’t propose a comprehensive package that would address pay and other benefits.

During the bargaining session, Starbucks did not propose an immediate wage increase and only guaranteed future annual wage increases of 1.5%, the union said.

Starbucks said in a statement that Workers United ended the round of negotiations early this week.

“We are ready to continue negotiations to reach agreements. We need the union to return to the bargaining table,” the company said.

According to Starbucks, the union demanded an immediate 64% increase in hourly wages and a 77% salary increase over the life of a three-year contract.

“This is not sustainable,” the company said in a statement.

It’s been a tough year for Starbucks. Globally and in the U.S., sales have fallen as consumers look elsewhere for caffeine. Baristas will reportedly receive a smaller annual raise next year than in previous years as sales decline.

Starbucks Workers United represents more than 500 company-owned Starbucks locations.

Starbucks baristas aren’t the only workers striking during the last-minute holiday rush. Amazon Workers at seven facilities went on strike Thursday to pressure the e-commerce giant to come to the negotiating table.