A protest by Starbucks employees over the company's new uniform policy got bigger on Thursday.

Starbucks Workers United, a union for the company's U.S. employees, reports that over 2,000 baristas in 120 American stores have been striking since Sunday, disagreeing with the recently introduced dress code.

From Monday, Starbucks is introducing new rules about what baristas can wear beneath their green aprons. Staff in company-run and franchised shops in the US and Canada must now wear plain black shirts and trousers or jeans in khaki, black, or dark blue.

Previously, baristas had more freedom to wear various dark colors and patterned shirts. Starbucks stated the updated rules will highlight their green aprons and give customers a sense of recognition, as they aim to create a friendlier atmosphere in their coffee shops.

However, Starbucks Workers United, the union for employees at 570 out of Starbucks' 10,000 American stores, argued that the dress code should be discussed and agreed upon together.

Paige Summers, a Starbucks supervisor in Hanover, Maryland, believes Starbucks has lost its focus. She argues that instead of valuing the baristas who create the Starbucks experience, the company is concentrating on less important issues, such as a strict new dress code. She added that customers are unlikely to be concerned about employee clothing colours when they are facing long wait times for their orders.

Summers and others also criticised the company for selling Starbucks-branded clothing styles on an internal website that employees were no longer permitted to wear at work. Starbucks stated they would provide each employee with two free black T-shirts when the new dress code was announced.

On Wednesday, the Starbucks Workers Union announced that 1,000 employees had participated in walkouts across 75 stores in the US. Starbucks stated that the strikes had a minimal effect on its 10,000 company-run locations in the country, with some stores temporarily closing for under an hour.

Starbucks stated that it would be better if the union focused on negotiations instead of protesting by wearing black shirts. They added that over 99% of their stores are currently open and serving customers, as they have been all week.

Readers of the Associated Press expressed varied opinions on the dress code, with some arguing that Starbucks' baristas' complaints were minor, as many retailers have similar requirements. Others felt Starbucks should prioritise beverage quality and prices, and employee satisfaction, rather than strict dress codes.

Maddie Mucklow, a Starbucks manager in Seattle, has expressed her support for the recently introduced regulations.

Mucklow admitted the new dress code was a challenge for her store's employees. However, she believes it creates clearer guidelines for professional appearance, allowing them to support each other while still expressing their personal style.

Since 2021, Starbucks employees, organised as Starbucks Workers United, have been forming unions in stores across the U.S. Despite agreeing to resume negotiations in February 2024, Starbucks and the union have not yet reached a contract agreement.

This week, the union stated they have officially complained to the National Labor Relations Board, claiming Starbucks has not negotiated the new dress code.