Organizers say the strike involves more than 1,000 workers, making it the biggest multiday work stoppage ever by Starbucks Workers United, the labor group that’s prevailed in elections at about 270 of the chain’s cafés this year. Workers at a few dozen locations that aren’t stopping work for all three days plan to support the effort by striking for a day or two, according to the union. 

The walkout underlines the rising tension between the coffee giant and its union employees, who have tried to secure a collective-bargaining agreement for more than a year without success.

• Sign up to get breaking news email alerts sent directly to your inbox

“We just want to show Starbucks that we’re going to continue escalating until they respect our right to organize and actually come to the table to bargain in good faith,” said Maggie Carter, a leader in the nationwide union campaign. “As long as Starbucks continues to fight us, we’re going to continue to fight back.”

Shares of Starbucks fell as much as 1.9 per cent in New York on Friday.

The coffee chain said the vast majority of its stores where employees were protesting have remained open for business. 

“It is unfortunate that Workers United continues to spread misleading claims,” Starbucks spokesperson Andrew Trull said in an emailed statement. “We remain focused on working together and engaging meaningfully and directly with the union to make Starbucks a company that works for everyone.”

Carter said union contract talks at her Knoxville, Tennessee, store began last week and ended within minutes when company representatives walked out over a dispute about the union’s desire for some workers to be able to participate via Zoom. Organizers around the country have been pushing Starbucks for better pay and protections against benefit cuts, among other things. Carter’s location isn’t part of the strike, but she is helping coordinate the work stoppage.

Lawmakers including Senator Bernie Sanders tweeted their support for the strike on Friday. 

While the campaign has so far organized only a small fraction of Starbucks’s 9,000 corporate-run U.S. locations, it has spread rapidly across the country this year. It helped inspire similar first-ever organizing victories at other companies, such as Apple Inc., Chipotle Mexican Grill Inc. and Trader Joe’s Co. 

However, the pace of new Starbucks unionization petitions has slowed in recent months, as workers allege the company has been retaliating in stores and stonewalling them at the bargaining table. Starbucks Workers United won its first election at a café in Buffalo, New York, a year ago, and those workers still don’t have a union contract.

U.S. National Labor Relations Board regional directors have issued dozens of complaints accusing Starbucks of breaking the law to defeat the union campaign, including by excluding unionized stores from new benefits.

Agency judges recently ordered the company to reinstate fired activists in Michigan and Kansas, and a federal judge issued an injunction ordering the reinstatement of seven union supporters at a Memphis, Tennessee, store. NLRB members ruled last month that Starbucks illegally refused to negotiate with the union at a café in its Seattle hometown. Starbucks has denied wrongdoing and said that all claims of anti-union activity are “categorically false.” The company has filed its own claims with the NLRB accusing the union of refusing to negotiate in good faith.

Workers previously held a one-day strike last month, in which the union said around 110 stores participated. Pro-union employees see pressure from the public as leverage to help them win concessions from the company. The union has so far stopped short of calling for a general Starbucks boycott, but this month urged customers not to purchase the company’s gift cards this holiday season.