Striking Starbucks baristas have increased their numbers as a five-day work stoppage expanded, shuttering hundreds of stores across America on Christmas Eve.

The union, Starbucks Workers United, represents employees for 525 locations of the coffee retail giant. It forced more than 300 stores spanning a dozen cities, including New York, Los Angeles, Boston, and Seattle, to close on the last day of a planned walkout, according to a report from Reuters.

In a released statement, Starbucks Workers United projected that the Christmas Eve strike would be the largest ever against Starbucks.

“These strikes are an initial show of strength, and we’re just getting started,” one Oregon-based barista said in the statement.

“Our sympathies to all the people who were hoping to snag that $5.9k espresso machine for Christmas,” wrote the union in an X post.

With over 10,000 locations across America, the closed stores are a fraction of the company. A spokesperson for Starbucks told Reuters that the company expects a “very limited impact” on its overall operations, with 97 to 99 percent of stores still open for business.

The strike began on Friday after both sides hit an impasse earlier this month during negotiations over wages, staffing, and work schedules.

The union rejected an offer that offered no immediate wage increases but promised a 1.5 percent raise in the future. The union complained that the company had pledged to reach a deal by the end of the year, but has yet to present “workers with a serious economic proposal.”

“We are ready to continue negotiations when the union comes back to the bargaining table,” the company spokesman said.