The union representing thousands of Starbucks workers in the US is staging a walkout on one of the coffee chain's busiest days of the year.
The action comes amid a bitter fight between Starbucks and Starbucks Workers United, which started organising workers at the company in 2021.
The two sides are fighting over pay, scheduling and other issues.
Roughly 200 stores are expected to be affected by the 16 November work stoppage.
Barista Michelle Eisen, one of the union's leaders, said the company could afford to "do better by its workers".
The protest is the second to coincide with Starbucks' 'Red Cup' day, when the company distributes reusable, holiday-themed cups.
In some locations, the walkout is set to last just a few hours, while in others it is expected to close the branch for most of the day.
The union said the action was aimed at calling attention to Starbucks' refusal to fairly negotiate contracts with the unionised stores.
Members are also protesting work conditions, including inadequate staffing on promotional days.
Ms Eisen said she expected more customers and community activists to join the action this year in a warning sign for the coffee brand.
"That's what's going to set this apart," she told the BBC. "That's what should scare the company. Their reputation is everything."
Starbucks, which operates roughly 10,000 stores across the US, said it did not expect major disruption.
It said it had spent hundreds of millions of dollars on higher wages, training and new equipment and it blamed the union for delays in talks, noting successful negotiations at several stores in Canada.
"Starbucks remains ready to progress in-person negotiations with the unions certified to represent partners," the company said in a statement.
Since 2021, workers at about 350 of the company's roughly 10,000 locations in the US have voted to join the union.
Starbucks has fiercely opposed the campaign.
Union members say it has dragged its feet at the negotiating table and gone so far as to fire workers and shut stores in an effort to stop the movement.
Administrative law judges in the US have found the company has repeatedly violated labour laws.
Starbucks, which typically appeals the findings, has denied wrongdoing.
Last year, former boss Howard Schultz was forced to appear before Congress to answer for the union's claims.
The union campaign at Starbucks has been closely watched, and is credited with helping to galvanise workers at other companies.
Ms Eisen, who was involved with the first Starbucks store to unionise, said watching other unions win big wage increases at other companies, such as UPS, had been "bittersweet".
"It feels like this campaign really lit a fire under the labour movement in this country and we are still sitting here fighting super hard," she said.