Strikes by Starbucks baristas protesting the company's new dress code intensified on Thursday.

Over 2,000 Starbucks baristas across 120 US stores have been striking since Sunday, according to Starbucks Workers United, a union representing workers at the coffee giant, in response to the updated clothing policy.

Starbucks implemented new restrictions on attire worn under the green apron, effective Monday. The dress code requires staff in company-operated and licensed stores across the US and Canada to wear solid black shirts and khaki, black, or dark-wash jeans.

Previously, baristas could wear a wider range of dark colours and patterned tops. Starbucks claims the new rules will highlight their green aprons and create a familiar feel for customers, aiming to build a warmer, more welcoming atmosphere in their stores.

However, Starbucks Workers United, representing workers in 570 of Starbucks' 10,000 US company-owned stores, argues that the dress code should be subject to collective bargaining.

"Starbucks has lost its way. Instead of listening to the baristas who create the Starbucks experience, they are focusing on the wrong things, like implementing restrictive new dress code," said Paige Summers, a Starbucks shift supervisor from Hanover, Maryland. "Customers don't care what colour our clothes are when they're waiting 30 minutes for a latte."

Summers and others have also criticised the company for selling branded Starbucks clothing that employees are no longer permitted to wear during work hours on an internal website. Starbucks stated they would gift each employee two free black t-shirts when announcing the updated dress code.

On Wednesday, the Starbucks labour union said a total of 1,000 workers had walked off the job at 75 stores across the US. Starbucks claimed at the time that the strike had a limited impact on its 10,000 company-operated stores in the US. In some cases, strikes resulted in store closures lasting less than an hour, according to the company.

"It would be more productive if the union put the same energy into returning to the bargaining table as it is dedicating to protesting black shirts at work," Starbucks said in a statement. "More than 99% of our stores are open today serving customers — and have been all week."

Readers of the Associated Press shared mixed opinions expressing different viewpoints on the dress code. Some argued that Starbucks baristas had little reason to express discontent, noting that many retailers require specific employee attire. Others suggested Starbucks should focus on improving drink quality and prices, as well as keeping employees happy, rather than concerning themselves with their clothing.

Maddie Mucklow, a Starbucks store manager in Seattle, said she supported the new regulations.

"Honestly, I think the dress code is a difficult shift for the partners at my store," Mucklow said. "But the dress code gives us a more consistent boundary for how to best represent each other while still keeping our individuality."

Starbucks Workers United began organising union for stores in the U.S. beginning in 2021. Starbucks and the union have not yet reached a contract agreement, though they have agreed to return to the bargaining table in February 2024.

The union said this week that it had filed a complaint with the National Labor Relations Board, accusing Starbucks of failing to bargain over the new dress code.