(The Hill) — Amazon workers in multiple countries went on strike for Black Friday, the busiest shopping day of the year, to protest the e-commerce giant’s labor practices.

The strike is organized by the UNI Global Union, which represents workers around the world and said it has mobilized workers from more than 30 countries, including Italy, Germany and the U.S., to speak out against Amazon’s treatment of employees.

Hundreds of workers were striking on Friday at warehouses in Coventry, U.K., and in multiple German cities, Reuters reported. Additional walkouts were expected later in the day in other countries.

Officials with the GMB Union, a large trade union in the U.K. that organized protesters there, wrote on the platform X that the strike on Friday was “the biggest industrial action in Amazon’s history.”

The effort is part of the “Make Amazon Pay” campaign, which has organized strikes for the past four years. Christy Hoffman, general secretary of UNI Global Union, said workers around the world are “standing up to Make Amazon Pay.”

“This day of action grows every year because the movement to hold Amazon accountable keeps getting bigger and stronger,” Hoffman said in a statement. “Workers know that it doesn’t matter what country you’re in or what your job title is, we are all united in the fight for higher wages, an end to unreasonable quotas, and a voice on the job.”

Strikers argue that Amazon pays warehouse workers lower wages compared to employees in other sectors of the company and for better health and safety policies. Some also raise concerns about the e-commerce corporation’s environmental footprint.

Jessie Moreno, an Amazon Teamsters member from Local 396 in California, said she and other workers “are on strike against Amazon’s unfair labor practices.”

“We have taken our picket line across the country and now we’re joining our colleagues from around the world to demand respect, fair wages, and a workplace where our health and safety are a priority,” Moreno said in a statement. “Amazon is no match for the power of its workers united.”

Amazon spokesperson Mary Kate Paradis said the “vast majority of these allegations are false or misinformed.”

“The fact is Amazon has created millions of good jobs, while helping create and support hundreds of thousands of small businesses around the world. We offer great pay and benefits for our employees,” Paradis said in a statement to The Hill, “with great career opportunities, and provide a modern and safe working environment for all.

“We continue to invest in the countries and communities where we operate, and we’re proud to be the world’s largest corporate purchaser of renewable energy,” Paradis added. “That’s part of our drive to be net zero carbon by 2040, with billions already invested in packaging reduction, clean energy and electric vehicles.”